Manual · for version 1.4.6 · View on GitHub

This manual comes from the public repository of the Home Assistant integration. It still uses the old name OpenThermostat, and calls the box the E32: the BBQKees Gateway E32 V2 that Emthera runs on today.

OpenThermostat reference: how it works and the details #

The firmware and the project's main repository are not public at the moment. What these guides say about downloading the firmware or a release ZIP from GitHub, updating the E32's firmware from Home Assistant or with Check for updates, and the tester program's GitHub form does not work for now. The Home Assistant integration is installed and updated through the Marketplace as described. A few references to pages that are not public have no link here. Questions or problems: open an issue.

This is the reference for OpenThermostat: the E32 V2 on your boiler's bus, with the Home Assistant integration. It explains how things work and lists the details. To set up your thermostat step by step, read the user guide first. Installing a new E32, updates and troubleshooting are in the installation guide.

The E32 controls the boiler only after you confirm the takeover; the guided Boiler test and takeover on the Boiler page is optional, and nothing else in this reference makes the E32 control the boiler. A new E32 picks its route from the boiler bus: while your old thermostat still asks the boiler for heat, it first runs a trial run beside it and compares; without one it goes straight to the boiler test. You can always choose the other route (see The attended switch-over).

Supported boilers: EMS Classic (EMS 1.0), directly on the bus or through an adapter such as the Bosch EasyControl Adapter. EMS+ (EMS 2.0) boilers are read, and controlled only once their model is verified; today no EMS+ model is (see EMS+ boilers).

Home Assistant is optional. The room plan, week programs and Bluetooth sensors live on the E32 and work without it. Home Assistant adds its own sensors and thermostats as room sources, a dashboard, heating advice and energy inputs.

Contents #

1. Where do I set what?
2. The dashboard in Home Assistant
3. Setting up the E32: the details
4. Home Assistant: the details
5. Rooms: changes, windows, away and holidays
6. Learning: how the E32 tunes itself
7. Energy, gas and warnings
8. Radiator valves
   • Shelly devices: floor pump, probes and valves
9. The trial run and the switch-over
10. Boiler settings (preview)
11. EMS+ boilers and boiler recognition
12. Backup and restore
13. Logs and the diagnostics console
14. Tidy entity IDs (optional)

Where do I set what? #

Settings → … is the last tab of the OpenThermostat dashboard. With the dashboard shown, Configure has two items, Open the settings page and E32 connection (see below); each row names the one place on the Settings tab. Without the dashboard, Configure keeps every setting in its own item under the same names (Rooms, House, Heating and boiler, Energy and outdoor temperature, Notifications, E32 devices, Dashboard and name, Advanced and diagnostics).

Both places count. The house and heating settings (house mode, holidays, the away temperature, the comfort style, Smart warm-up, weather compensation and the water temperature limits) stay adjustable on the E32's Home page while Home Assistant is linked; the page says "Also adjustable in Home Assistant". The E32 holds the settings. A change on the E32 applies at once and Home Assistant shows it within a few minutes at most. Home Assistant never puts its own older copy back: a Configure form sends only what you changed in it. If both change the same thing at the same moment, the E32 refuses the second save and asks to try again.

The room plan is stored on the E32, and the E32 runs it. With Home Assistant, the HA room editor is the main place to edit it; it reads the plan from the E32 and writes it back. Bluetooth sensors stay paired on the E32, so they keep working without Home Assistant; the E32 shares them with Home Assistant, where each sensor appears as its own device and can be chosen as a room source.

The Settings tab #

After an update the page can be older than the integration. The panel then says "OpenThermostat was updated. Reload the page to use the new version." with the button Reload and opens no screen until you press it, instead of mixing old and new. The same button stands beside "The settings could not be loaded. Reload the page." (a part of the panel did not load) and a screen that could not be read.

The last tab of the OpenThermostat dashboard, Settings, holds the settings of the installation in seven entries, each with an icon and what is set now: Rooms, House, Heating and boiler, Devices, Notifications, Energy and outdoor temperature and Installation (the name and the dashboard, the E32's system log and time zone, the tester program, and under Maintenance restoring a backup, tidying entity IDs and removing old Home Assistant rooms). On a wide screen the right side shows the installation at a glance: every room with its temperature and state, the boiler and what it does, whether Smart warm-up and weather compensation are on, and the next holiday; each opens its part. Each room card on the Overview has a Settings button (bottom right) that opens its room here. The tab is there for an installation on the E32 room plan with the dashboard shown; without the E32 connection, Rooms, House, Heating and boiler and Devices say "Connect the E32 first: Configure → E32 connection." The tab's own files load when you open it; other Home Assistant pages carry only its small core.

Each screen shows the value in use now, with one line of explanation under each choice and the rest behind More. Times and dates follow Home Assistant's language and clock (24 hours in Dutch). It reads what Home Assistant already knows (the room plan it last read from the E32); the live values (temperatures, targets, batteries) come from the entities. A screen saves with the bar at its bottom (Save, Undo) and sends only what you changed, with the same checks and the same E32 writes as Configure, so a setting means the same in either place. When the same setting was changed on the E32 or in Configure meanwhile, it says Changed elsewhere, keeps your change marked and shows the rest as saved; Save again to keep yours. A change you leave unsaved stays while you look at another entry ("Not saved" on its row). Only an administrator of Home Assistant can save; others see the same screens without fields to change. A screen that cannot read the E32 says why (no connection, the password changed, firmware without the setting).

Rooms and House #

Rooms shows every room as a card: the temperature now, the target, its state as a coloured label (orange On, amber Heat along only, grey Off), what it does now ("Heating: 20.1 → 20.5 °C", "Paused: a window is open") and its next reset time. + Room opens an empty room. A room's screen has a section for each part, closed until you open it, each with one line of what is set; the panel remembers which you opened. On a wide screen the rooms stay listed on the left.

Remove room at the bottom asks first; the E32 forgets the room and Home Assistant removes its devices, as Configure does. A part this E32 firmware does not have is not shown.

House has three parts: Presence and away temperature (who lives here, away after, the temperature when nobody is home), House mode and holiday (the modes the E32 offers with their explanation, Holiday ends for a holiday that starts now, Planned holidays with Plan a holiday and remove, Temperature on holiday, and Stop holiday while one runs: the house goes back to the mode it had before) and Room defaults (comfort and night without a week program, the pauses after a window or a door opens: the values a new room starts with; each can be changed per room on the room screen). The window and door contacts are on each room's screen; an old link to them opens the room.

Heating and boiler, Devices, Energy #

• Heating and boiler lists Smart warm-up and weather compensation, Water temperature limits, Heating circuits (with a circuit pump), Comfort and boiler care, Boiler model and Boiler settings (preview), each with an icon and what is set now (Boiler settings: Off, or On with the changes of today). Each opens its own screen; every field has one line of help and the rest behind More:
  • Smart warm-up and weather compensation: the two switches, the Comfort style as three buttons with the chosen one's line under them, and the Water temperature in hard frost (−10 °C).
  • Water temperature limits: the boiler's own maximum on top ("The boiler itself goes up to 75 °C"). With Lowest water temperature: automatic on, the line under it says the value the E32 uses now ("Lowest water temperature now: 42 °C (learned)") and the lowest value appears once you switch it off. A highest temperature above 50 °C with floor heating, or above the boiler's own maximum, asks once before it is saved.
  • Comfort and boiler care: a compact list in two groups, Set by the E32 itself and Fixed settings: each setting with its value now and, for the first group, the switch Automatic in the row. Tap a setting for its own screen: its explanation and your own value. Back to automatic for all and Back to start values (red) each ask first and are saved at once.
  • Boiler model: the list of models; what the E32 recognised on the bus on top.
  • Boiler settings (preview): see Boiler settings.
• Devices has the three blocks of the E32's System → Devices page, each with its own screens (the overview row says, for example, "2 Bluetooth sensors · 3 Shelly valves"):
  • Bluetooth sensors: the sensors with their temperature, how long ago they reported and "Measures for" the rooms that use them (or "Not assigned to a room yet"). A sensor's screen has its Name (a name taken from the room is marked "automatic"; Keep this name makes it your own) and Measures for: choose the room, and the sensor becomes that room's first temperature source and leaves every other room (one save on the E32). If the entity IDs in Home Assistant still carry an older name, a notice offers Tidy entity IDs. Forget sensor (after a question; the E32 deletes its key and restarts once). Pair a sensor: the E32 listens for about 30 seconds and the list under Choose your sensor shows what it hears with its signal (strong, fair, weak); Search nearby looks again ("Searching… (up to 90 s)" while it runs; the button is off only while a search really runs). Choose one, give it a Name, check the Sensor type (pvvx, Shelly H&T or Xiaomi; the screen guesses it and says so) and, for an encrypted sensor, enter its 32-character key, which only the E32 keeps; then Pair. Saving restarts the E32 once, about 30 seconds later. At most 8 Bluetooth devices.
  • Shelly devices: each with what it does, its address and whether it answers. Shelly device (the screen is called Add a Shelly device: the address, what it does, a name and the password; the E32 tests the address when you save, which takes up to 16 seconds) and Remove device. The password goes to the E32 only: Home Assistant does not keep it and never shows it again. On The Pill's screen each probe gets its pipe (Probe roles, then Save probe roles). On a BLU Gateway's screen, Valves lists its valves with their room (Remove, or Add a valve by its number) and Look for valves at the gateway asks the gateway for the valves it has paired: tap one to add it (it takes at most 5 valves).
  • Batteries: every battery of the installation on one list, the lowest first, each with its room, its kind, "Low / Fine / No report" and when it last reported; Warn below sets the one limit (15, 20, 25 or 30 %). The row on Devices says "{n} devices · {m} low".
  • On the boiler bus: the devices the E32 hears, nothing to set.
• Energy and outdoor temperature is Configure's form on one screen: one line of help per field (Configure's whole explanation behind More), and each chosen sensor's value now, large under its field, following Home Assistant (1.4.1).

Notifications #

Notifications (1.4.1) asks two questions, each on its own screen; the overview row says Off until something is on, then what is on ("On: the house, Living room"). At the top one status line says where messages go now: "Messages go to Ben (Pixel 8) · Anna without a phone · house messages to Anna (no phone: in Home Assistant)." (green while someone is reached, red when a chosen phone is no longer found, grey otherwise).

• Who gets messages: a row per person with their phone ("Pixel 8 (Home Assistant app)", a notify service, "… (not found)" or No phone) and the label Also house messages when that is on. Tap a person: one choice Phone or app (the app on their own phone on top and already chosen while nothing is; Save stores it, Undo goes back to No phone; leaving without saving keeps nothing) and one switch Also messages about the house (off by default; only the people with it on get the house messages). The help under each follows what you chose.
• Which messages: The house with Notify about the house; while it is on, the Problems and the Maintenance messages, each with one grey line of what causes it ("The boiler reports a fault."). The help under the switch says who gets them ("They go to: Anna."), or that nobody does yet, or "Off: no messages about the house.". Rooms below it: a row per room with its summary ("On: window open, too cold" or "Off"); a room opens its own screen at Notifications for this room, where its switch, its messages and its Recipients are set.
• Recipients (1.4.2): who gets a room's messages, chosen per room on the room's screen. The line says it: "Messages about Study go to Anna and Ben.", "… go to everyone with a phone." (a room that was never set) or "… go to nobody; they show in Home Assistant only." (an empty list). Someone without a phone shows as "Anna (no phone: in Home Assistant)"; a chosen person Home Assistant no longer knows is named under "Not found in Home Assistant". After the update every room with notifications on keeps the people it had; the room's Persons (presence) are a separate setting.
• Batteries (1.4.2): every battery of a thermometer, radiator valve, window or door contact or setting device is watched with one limit, Warn below (15, 20, 25 or 30 %, 20 by default; Settings → Devices → Batteries). The message names the device ("The battery of the radiator valve Landing valve in Bedroom is at 18 %"), comes again after 7 days while the battery stays low, and stops when it is 5 points above the limit. A device with a battery that has not reported for 24 hours is reported as "stopped reporting": probably empty. The sensor Batteries low counts them; the Overview shows a line only while it is above 0.

Save stores what you changed on that screen, with the same checks as Configure (switched on without a message: "Choose at least one message, or switch notifications off.", under the field). Home Assistant keeps these settings, not the E32.

Installation #

Installation (1.4.1; it holds what 1.4 called Dashboard and name and Advanced) holds what belongs to the installation as a whole. The page does not ask the E32 until you open a row.

• The installation's name (1 to 80 characters) and Show the OpenThermostat dashboard, the same as Configure's. Hiding the dashboard asks first, because this tab goes with it; Configure then has all its items again. A new name reloads the integration once; devices and their history stay.
• E32 system log: sending the E32's log to a syslog server (Send to a syslog server, the server's IPv4 address, the UDP port, the level, the E32's own and the boiler bus messages; the fields for sending show once it is on), the level the E32 keeps for its own log page, and the "still running" message. Opening it reads the E32; Save writes all fields at once and reads them back.
• E32 time zone: the zone the E32 runs the week programs in, with what the E32 and Home Assistant use now. Use the time zone of Home Assistant chooses Home Assistant's own zone. Save asks first, because the E32 restarts once to use it; the heating continues after about a minute. When the E32 holds another zone than the screen showed (changed on its page meanwhile), nothing is saved.
• Tester program: the switch Take part in the tester program; while it is on, the bus recording's state ("Recording: 12 of 30 minutes, 1,234 messages."), Start a bus recording (30 minutes) or Stop the bus recording, and Share result (see EMS+ boilers). Each action happens at once and says what it did.
• Status of the room setup (only while old Home Assistant rooms are left): the texts of Configure's checks of the old rooms, read only.

Under the heading Maintenance, each part opens in place, with the same questions and sentences as Configure:

• Restore settings to this E32: the backups Home Assistant keeps (date and time, daily, manual or before a restore, the size, with passwords and keys), or a Backup file saved on the E32 page with its Passphrase of this backup (empty: restored without passwords and keys). Another E32 (replacing a broken one) takes the address and password of a new E32. Check backup lets the E32 check it and shows what changes; Restore asks first ("Restore these settings?"; onto another E32 one question says both: these settings go onto it, and Home Assistant uses it from now on), then shows the progress until the E32 is done, and what to enter again. See Backup and restore.
• Tidy entity IDs: the list of IDs Home Assistant would give today (only the unused ones, or all), Tidy after the question, and Undo for 30 days. See Tidy entity IDs.
• Remove old Home Assistant rooms (only while one is left): the rooms, what happens to each room on the E32, and Remove old Home Assistant rooms after the question, with the progress.

Configure #

Configure is Settings → Devices & services → OpenThermostat → the gear icon. Every submenu has ← Back; after you save you are back in the menu, and Done closes Configure.

With the OpenThermostat dashboard shown (1.4), the settings live on its Settings tab and Configure has two items (1.4.1):

Without the dashboard (and so without its Settings tab), Configure keeps every setting in its own item, nine in all; the Configure paths elsewhere in this guide are these:

The Repairs dialogs (for example Confirm again that the E32 may control the boiler) use Configure's own steps whatever the menu shows.

The dashboard in Home Assistant #

The OpenThermostat dashboard in the Home Assistant sidebar has these tabs, in this order: Overview, Rooms, Boiler, Learning, Diagnostics and Settings. Every tab uses the whole width of your screen, like the Overview (1.4.3): on a phone one column, on a laptop two, on a large monitor up to four. Diagnostics has few sections, so since 1.4.4 each of them spans two columns and the tab fills a large monitor; only a section of half-width tiles side by side (Comparison's E32 and thermostat) keeps one column. While the house mode is Summer, every tab starts with a grey banner: "Summer mode: the heating stays off until you switch this off; hot water and frost protection stay." with the button Switch summer mode off, which asks once ("The house mode becomes Automatic.") before it switches.

• Overview, from top to bottom: the house card, then Rooms, Today and House. On a wide screen the house card goes across the whole width, Rooms is two columns wide with its room cards two by two, and Today and House stand beside it (1.4.3).

  • The house card shows the whole house at a glance:
    • A status band in the colour of what the boiler does now, in white letters: orange while heating (with the water temperature), blue for hot water, grey for "Boiler resting". While rooms want heat, a second line says how many and what the boiler request is. The band also says how hard the burner works and the boiler's display code ("burner 37 % · code -H"; point at it for what the code means): on a wide screen on its right, on a phone under the words. A problem comes first: the band turns red and says "Attention" with the first reason. Tap it to open Repairs; All reasons lists every reason.
    • The house mode, in a row of its own under the band: House mode with the mode large and, beside it, what it means in one line ("Someone is home", "Always the week programs", "Every room at most 15 °C", "Until Sat 14 Nov", or the summer sentence), and the next planned holiday ("Next holiday: 19 Dec – 3 Jan"). Tap it to open the house mode control. When the E32 suggests summer mode (five warm days) or its end (three cold days), a grey row under it asks the question with one button to answer it ("Switch summer mode on").
    • Today's figures, large. The first is the room that is on, with its temperature, its target and why it heats or not (every room also keeps its own card under Rooms, the rooms that are on first). Then Hot water (the taps so far today, or "running now", and the hot water's temperature), Gas today (heating and hot water together) with a small line of the last 7 days beside it and the average day of the week before under it, and Burner starts today (with how many came in the last hour). While the band shows a problem, Heating (on, with the water temperature, or off) is added, because the band then cannot say it. A figure that your boiler or the E32 does not report is left out. The gas and the burner starts are read from Home Assistant's statistics; on the first day, until it has some, they show "—".
    • A day strip from midnight until now: when the boiler was heating, making hot water or keeping it warm, with the hours and "now" under it. Point at a part for its start and end time.
  • Rooms: a card per room, with the icon of its heating type (radiators or floor heating), its name, its temperature, large, with the target beside it, its state as a coloured label (orange On, amber Heat along only, grey Off, grey Summer while the house is in summer mode), and, in one line, what it does now: window open, away, warm enough, Smart warm-up heating early, and so on. The same line is the Reason sensor of the room. While the room follows its week program, the line goes on with the program: the level now and the next step ("Comfort until 22:30, then Night 18.0 °C"; a level the planner does not name shows its temperature). A holiday planned before that step is the next step ("then Holiday 12.0 °C"). It is left out while something else holds the room (a temporary change, away, a holiday, an open window) or when the program changes nothing in the coming week. The times are the E32's clock (its time zone as Home Assistant last saw it in the E32's settings, else Home Assistant's own). A card shows a label only for what differs from the usual: Smart warm-up off (or on) when the room's own choice differs from the house's, and a valve with a problem in red; otherwise a quiet grey line says how far the radiator valves are open. A muted line names the room's next reset time ("Resets at 22:00 to 14 °C"), and Settings (bottom right) opens the room on the Settings tab.
  • Today: for each room that is switched on, when it warms up next and what it will be then ("Tomorrow Living room warms up from 06:10 to be 20.5 °C at 07:00"; a start on another day says "at 00:30 tomorrow" or "on 7 Nov"), and how the last warm-up went ("Today it was warm 4 minutes late" once today's warm-up is judged, else "Yesterday it was warm 4 minutes early"; "did not get warm within 3 hours" when it never got there). The start shown includes what free heat saves, and a line says how much later it is. While the house or room is away, on holiday or a window is open, no warm-up is announced; the line says why. In the trial run the lines say "would". When the room is warm enough by itself, the line says so ("Tomorrow Living room is warm enough for 20.5 °C at 07:00; if it cools down before then, the warm-up starts earlier"); in the first days, before the E32 has measured the room, the start is marked "(estimate)". A room that is off says that only frost protection keeps it warm. Under it one line on the water, for example "Outdoor 6.7 °C: the E32 asks 42 °C water", with ", on the line it learned for your house" added only when the line is the learned one (1.4.3; when no room asks for heat, what it would send once one does). How the E32 comes to that figure is on the Learning tab, under House and boiler.
  • House: Holiday (Plan opens the Settings tab's House mode and holiday, where you plan one; without the room plan, Configure) and Outdoor (the outdoor temperature). The house mode and the next planned holiday are on the house card on top (1.4.1); only while there is no house card (no heat request or boiler activity from the E32 yet), this section shows Home or away (tap it to change the mode) and the next holiday.

• Rooms (1.4.3): one card per room, four side by side on a large monitor, two on a laptop, one on a phone. The rooms are one section; below it, Bluetooth sensors lists the sensors that belong to no room, with a line Link to a room. Each room card shows, from top to bottom:

  • The top line: the heating type's icon, the room's name and its state. On a room that is On or on Heat along only the state is a menu: tap it to choose On, Heat along only or Off. Off and Summer are plain labels. Red or grey labels beside it name what differs from the usual: Window open or Door open, Smart warm-up off (or on) when the room's own choice differs from the house's, and a valve with a problem. The state stays beside the name, also next to a long name and on a narrow phone (1.4.5); the red or grey labels take a line of their own under them.
  • What it does now, in one line, with the program step ("Heating · Comfort until 22:30, then Night 18.5 °C"). It is the room's Reason sensor.
  • The arc: the measured temperature large in the middle of an arc, with a dot where the target is; tap the arc to open the thermostat of the room in Home Assistant. Beside it Target with − and + (0.5 °C a step; the card sends the change a moment after your last tap). Under it a quiet line says when the change ends: "At 23:00 back to 18.5 °C", or "Heats again once the window is closed". On a room on Heat along only the label is Heat along up to and the buttons change that temperature.
  • The presets: Program, Comfort, Eco, Night and Boost, the same row on every room that is not Off, the room's current one marked. On a narrow card (below about 330 px) the row wraps onto two rows with every chip whole; it never scrolls sideways (1.4.5). Program goes back to the week program; the others hold until the next switch time (Boost one hour). Without a week program Comfort, Eco and Night become the room's temperature without a week program, the chip whose level equals that temperature is the pressed one, and Program ends a Boost; when the levels are the Room defaults of Settings → House, a quiet line under the row says "Comfort, Eco and Night use the room defaults". On Heat along only Program switches the room back to On. Hold a finger or the mouse on Program to see where it goes.
  • The bar of today: the day from 0 to 24 hours in the colours of the levels (Comfort, Eco, Night), a mark for now, the hours under it and the levels of today in a line under that. A hatched part before a switch time is Smart warm-up heating early, and the line over the bar says when: "Smart warm-up starts 04:20 · warm at 06:30" (or "No early start: window open"). A room without a week program has no bar and says "No week program".
  • The last 24 hours: a small line, the measured temperature (blue) and the target (orange). Tap it for the full history. A room that has no measurements to draw yet says "Not yet 24 hours of measurements." (1.4.6); the line appears by itself once there are some.
  • The devices of the room, as tiles with an icon: the thermometer (its temperature, humidity and battery), other sources, the setting device ("set to 21 °C"), each radiator valve ("4 % open · battery 41 %", or "set to 19 °C" for a valve that is driven by temperature), windows and doors ("open since 12:08" in red, or "closed"), and persons ("home" or "away"). A setting device that only reports a range of temperatures (for example a Bosch Room thermostat II) shows its lower value, "set to 21 °C" (1.4.4). A valve that reports no setting of its own shows the temperature of its room, "set to 19 °C". A valve whose message the E32 cannot read says in red message too large (2.3 KB) and counts as a valve problem on the card (not a Repair). A valve's second line is otherwise what the E32 found: put back to 17 °C (someone turned it and the E32 put it back), running its own program (Home Assistant shows it as soon as the valve reports its own program, since 1.4.6; the E32 itself says it up to an hour later), switched off by you, or not responding to the E32. Tap a tile to open the device in Home Assistant.
  • The buttons at the bottom: Week program and Settings open the room's own screen on the Settings tab. A room that is Off shows only its temperature, where it comes from and the button Switch on now. While the house is in summer mode the card says so and a tap on a control explains that summer mode comes first. While the E32 is switched off or has not reported, the card says "The E32 is not reporting yet." A value a device does not report shows "no measurement", never "Unknown". What the E32 learns for a room is no longer here; it is on the Learning tab.

• No Week program tab since 1.4.1: a room's week program is on its own screen, Settings → Rooms → the room → Week program (the planner, with the room's reset times as markers above the days and as a list under it, and the room's Smart warm-up). The planner card of all rooms (custom:openthermostat-e32-week) can still be added by hand to a dashboard of your own; see the user guide, step 11.

• Boiler, in the order you need it. It opens with the Now card: a band in the colour of what the boiler does, in white letters (orange for heating, blue for hot water, grey for resting; red for a fault, with what to do). The band says it in words, with the display code ("Code -H: heating"), and on its right it shows the connection with the boiler and whether the boiler serves hot water. Under the band are four large figures: Water to heating (what the E32 asks, "E32 asks 30 °C, sent 35 °C" when the boiler got another value, for example its own minimum, and the most it asks near the target), Water back (with the difference), Burner power (a small arc and a word, from "burner off" to "full fire") and Starts in the last hour (calm, or switching on and off too often, and today's starts). Tap a figure for its history. A figure that your boiler does not report is left out. Then, from top to bottom: Advice (the heating advice, when there is any), Today and this week (the gas for heating and for hot water, the burner starts and the burner time of today, one chart with the gas per day of the last week, and the burner hours per day), Hot water (its temperature and target, the taps of today and a 24-hour timeline), Last 24 hours (graphs of the water temperatures, the burner power and the hot water), What the boiler reports (the values your boiler sends, in groups) and Boiler settings. On a wide screen Today and this week, Hot water and What the boiler reports stand side by side, the last one two rows high, with Last 24 hours and Boiler settings under them (1.4.3); on a phone What the boiler reports comes before Last 24 hours. A section is hidden while the boiler reports nothing for it, so a heading never stands over nothing. Yesterday is not here; it is on the Learning tab.

• Learning (1.4.3; until 1.4.2 the tab also held the two switches): everything the E32 learns, on one tab, so you read what it did. The two switches (Smart warm-up and Weather compensation) are under Settings → Heating and boiler; a quiet row at the bottom of this tab links there and says how they are set. From top to bottom:

  1. What the E32 knows: a ring with how much of your house the E32 knows ("The E32 knows your house: 62 %") and one line. Under it is the learning path, one label for each thing the E32 learns: green with a check when it is learned, amber with a clock and what it still needs when it is still learning ("Model of Bedroom · 2 of 3 days good", "Warm on time Bedroom · 2 more mornings"). A part the E32 cannot judge yet has no label. The old list "Still to learn" is gone.
  2. Per room: one card for each room, the rooms that are on first.
     • A label: Learned (green), Learning with how far it is (amber: "4 of 6 warm-ups", or "the coolest water"), Heats along (a room on Heat along only) or Off.
     • Four facts, each with a figure and a line under it: how long one degree takes ("1 °C in 2 h 10 min · warming up with water of 40 °C"), how fast the room cools ("0.26 °C per hour · cooling at 5 °C outside"), the coolest water that warms in time ("42 °C") and the free heat ("+2.4 °C per hour · free heat in the evening (sun, cooking, people)"). A fact the E32 has not learned yet is a dotted tile that says what it still needs ("2 more warm-ups", "after the warm-up is learned", "not seen yet", "after a night without heating"), never a number.
     • Smart warm-up, in one line: "starts at 04:20, so it is 21 °C at 06:30", with "(estimate)" in the first days, "No early start: window open", or why none is needed.
     • Warm on time, last 7 mornings: seven dots, green when the room was warm on time, amber when late or early, an empty ring for a morning without a check, a weekday letter under each; the line under them says how yesterday went ("Yesterday warm at 06:34 (4 min late)").
     • The room model as a bar ("predictions 2 of 3 days good", or "trusted: its predictions hold").
     • The advice, if there is any ("Advice · …"), always with "Advice only: your week program stays as it is." A room on Heat along only shows the cooling and the advice for heating along; a room that is off says so in one line. Tap a row to open the sensor behind it.
     • Reaches 19 °C (14 days) (1.4.4, Heat along only): a tile "92 %" that says how much of the time the room was at its temperature while the house heated, counted in hours over the last 14 qualifying days. Before 14 days it says "still counting: day 6 of 14". A heat-along room with a week program gets no figure, because its target changes during the day. The room's screen says it in a sentence: "Reaches 19 °C 92 % of the time (14 days)".
     • Learn again at the foot of the card (1.4.4): a text button that asks first and then lets the E32 learn that room again. It shows only with an E32 that offers it (1.4.4 or newer).
  3. Today's plan: what the E32 plans, with the button Let the E32 plan the heating once it is ready (firmware that plans the heating only).
  4. House and boiler: the chart Water temperature by outdoor temperature with the standard line (dashed), the line learned for your house (solid) and the point of now. The point reads "6.7 °C outside → 34 °C", "E32 asks 42 °C" and "+8 °C for the rooms"; one sentence under the chart says how much warmer the water gets for every degree colder outside. Under the chart come the boiler's own figures, only those the E32 has: the highest water ("47 °C · highest water at 5 to 10 °C outside; the E32 asks at most 45 °C"), the rest ("10 min · rest each time it reaches its temperature"), where it burns steadily from and where it starts heating from. Until the boiler is learned, one sentence says so.
  5. Yesterday: four figures large at the top (how early or late the first room that is switched on was warm, the burner starts per heating hour, the gas for heating and the degree-days), then Noticed (yesterday compared with your own usual days, one line for each thing that stood out, with what can cause it; information only), the missed comfort of the last days as bars, and the rest of yesterday. A figure the E32 did not measure shows "—" and is hidden on the dashboard; the figures stay after a restart of Home Assistant or of the E32 (1.4.1).
  6. What it changed by itself: every change with its date ("9 Nov · …"), all of them when one day changed several settings, and a link to Settings → Heating and boiler → Comfort and boiler care.
  7. Worth checking: advice that is no fault, one line each (a room that stays too cold while it asks for heat, a burner that keeps switching on and off after the self-tuning had its chance). It is hidden while there is nothing.
  8. Who controls the boiler: the burner as information and the check before the E32 takes over; only in the trial run or while the takeover waits for your confirmation.
  9. The quiet row: Settings → Heating and boiler and one line, for example "Smart warm-up on · Weather compensation on · Comfort style Balanced".

  Every part shows only once it has something to say. On a phone the sections stand under each other in this order; on a large monitor the knowledge strip and the room cards go across, and the others stand two columns wide beside each other.

• Diagnostics: it starts with Connection with the E32, one line per question: does the E32 report to Home Assistant (and since when it has been silent), do the room values reach the E32 (when not: since when, the last value the E32 refused and why, and what to do), does the MQTT broker take the messages, which firmware runs (with a note when an update is waiting) and, while there are any (E32 1.4.4), "Messages the E32 could not read: 3, last: zigbee2mqtt/…, too large (7.2 KB)": every device message the E32 received since it started and could not read, with the last one (not a Repair). More details stand behind More. Then come the E32 itself, the Radiator valves (1.4.4: every valve per room, in the words of the room card: opening or "set to 19 °C", battery, "not responding", what the E32 found, and in red "message too large (2.3 KB)" for a valve whose message the E32 cannot read; a grey "shortened" beside a room's name (E32 1.4.5) means the E32 left some of that room's valve details out to keep the room within its size limit; it shows while the E32 reports valves), Thermostat on the bus (what a thermostat on the boiler bus asks, as the E32 hears it; mostly of use in the trial run), the energy and hot water counters, the raw boiler data and the hot water capability.

• Settings (last): every setting of the installation, on seven screens; see The Settings tab.

During a trial run a Comparison page opens from the Learning tab.

Setting up the E32: the details #

The user guide has the steps. This part adds the details.

Firmware, Wi-Fi and the first sign-in #

A new E32 first needs the OpenThermostat firmware over USB; see installing the firmware.

1. Power the E32. Without Wi-Fi settings it opens its own setup network OpenThermostat-xxxxxx (password openthermostat).
2. Join that network with a phone or laptop. The setup page opens by itself; otherwise open http://10.10.10.1/.
3. Choose your 2.4 GHz home network and enter its password. Settings are saved only after a successful connection.
4. Open the address the page shows on your home network. A new E32 is also reachable by its name openthermostat-xxxxxx (the end of its MAC address), for example http://openthermostat-a1b2c3.local/ where your network supports .local names.
5. Sign in with user admin and password admin. Then choose your own password (8–64 characters) under System → Password; until you do, the Overview reminds you. Home Assistant asks for this password when you connect it. A forgotten password can be reset to admin with the password-reset command over USB.

The time zone #

Week programs, "today" and the daily comparison use the E32's own clock. Go to System → Settings, section Time, check the time server and choose your time zone from the list. When the page suggests the time zone of your browser, Use this time zone fills it in. For a time zone that is not in the list, choose "Other" and enter its POSIX text under Advanced, for example EST5EDT,M3.2.0,M11.1.0 (US Eastern); any time zone and summer-time rule works. Choose Save settings and let the E32 restart. Without a valid clock the week program is not used and the room keeps its Temperature without a week program.

The status light #

The light on the E32's board sits on a different place on an E32 V2 (a single light) and an E32 V2.2 (a colour light), and the E32 cannot see which board it is. So the light stays off until you choose your board under System → Settings → Advanced → Status light. Choose only the name printed on the board: a wrong choice switches a part of the board that is no light. The choice works as soon as you save, without a restart, and the settings backup keeps it.

The light looks again every tenth of a second:

• On (green on a V2.2): the E32 has the network, the MQTT broker (when you set one) and has heard the boiler in the last minute.
• Slow blink, 1 s on and 1 s off (red): one of those is missing. Just after a restart this is normal for a few seconds.
• Fast blink, 0.2 s on and 0.2 s off (blue): a firmware update or a new set of pages is being installed. This wins over every other state.
• Two short flashes every 2 s (amber): the rooms are set to active control and the E32 waits for you to confirm the takeover; see the attended switch-over.

Between 22:00 and 07:00 the light is dimmed, once the E32 has the time from the internet. In the setup network (WiFi setup) the light blinks slowly: the E32 is not on your home network then.

Your boiler on the bus #

A newly installed E32 does not listen to the boiler yet. Under System → Settings → Advanced, tick Boiler bus (EMS) on, save and let the E32 restart. This only lets the E32 receive boiler data; it does not send heat requests. Connect the E32 to the boiler's EMS bus as described in the installation guide (switch the boiler off first).

Then open Boiler and check that boiler values arrive (temperatures, status). Under My boiler → Boiler model and picture, choose your boiler and Save boiler selection; this changes the name and picture shown and which table explains the display code. The E32 also recognises the boiler by itself: see boiler recognition. EMS Classic boilers are fully supported; an EMS+ boiler is read, but not controlled until its model is verified (see EMS+ boilers).

The Display code on the Boiler page and the Overview is shown in words, with the raw code next to it, for example a blocking fault with what to do. The words come from the manufacturer's manual for the chosen boiler model, or from a general EMS table; a code that is not in the table stays the raw code. A fault or lockout is marked as a warning or an error. In Home Assistant the Display code sensor keeps the raw code as its state, with the meaning, severity and advice as attributes, and the Now card of the dashboard's Boiler tab shows the meaning.

The E32 reads the boiler's own settings itself (heating on or off and its temperature, maximum burner power, pump run-on, hysteresis, minimum burner period, pump and hot-water settings) shortly after a start and then every 6 hours; from 1.1.0 it reads all of them, earlier versions only the heating limit. The Boiler page and Home Assistant show each with the time it was last read. Read heating settings under System → Diagnostics and system log → For the installer reads them right away. It only reads and changes nothing on the boiler; it waits while the boiler heats hot water (at most 30 minutes).

Not every boiler reports every value. Boiler → My boiler → What your boiler reports shows which values your boiler has (Values available), which it does not have (Not fitted on this boiler) and which have not come in yet (Not reported (yet)). Home Assistant only creates entities for values the boiler has; Show anyway reveals a value the boiler marks as not fitted. A value that stays 0 for at least 10 minutes while the boiler is working (the Bosch EasyControl Adapter, for example, leaves the boiler's water temperature target and the burner and 3-way valve bits at 0) is listed as not reported ("stays 0 while the boiler works") and shown as "Not reported" instead of 0 or "off"; Home Assistant hides its entity. A lifetime counter that the boiler or its adapter never fills in (burner starts and hours behind a Bosch EasyControl Adapter, for example) says "Not reported by this boiler or adapter" on the Boiler page, and in Home Assistant it stays unknown with the same words instead of 0 (1.1.0).

Bluetooth thermometers #

This example uses a thermometer with pvvx firmware; Shelly BLU H&T and Xiaomi Monitor 3 work as well.

1. In the pvvx configuration page, set the advertising format to BTHome v2. Unencrypted is simplest; if you enable encryption, note the 32-character bindkey. The older PVVX Custom format also works.
2. Place the sensor in the room, away from radiators, windows and direct sun, within Bluetooth range of the E32.
3. On the E32, open System → Devices and, under Bluetooth sensors, choose Search nearby. The list shows up to 32 of the strongest nearby devices. (With Home Assistant: the dashboard tab Settings → Devices → Bluetooth sensors → Pair a sensor does steps 3 to 5 for you: the search starts by itself; under Choose your sensor choose yours, check its Name and Sensor type, and choose Pair.)
4. Click your sensor and give it a clear name such as "Living room thermometer". Choose the profile Thermometer with pvvx firmware (BTHome); the panel guesses it from the device's name and says so. Enter the bindkey only if you enabled encryption; keys are stored on the E32 and never shown again.
5. Choose Save. The E32 restarts by itself after about 30 seconds to apply the change.
6. After the restart the sensor shows a temperature. "Waiting" means nothing has been received yet: check distance, battery and address.

Up to eight Bluetooth sensors can be paired. Readings stay valid for 15 minutes, so a sensor that sends every few minutes is fine.

Rooms on the E32 #

An E32 that was never linked to Home Assistant says "Not linked to Home Assistant — you edit rooms here." on the Rooms page.

1. Choose Add room and give it a name, for example Living room. A new room opens fully. A saved room is a card that opens with a click, and its blocks Temperature, Week program, Windows and doors, Persons and (E32 1.4.4, saved rooms) Learning fold open separately; a closed block shows a one-line summary. The page remembers in this browser which blocks you opened.
2. Set the State to On and the Heating type (radiators or floor heating). Off until switches a room off until a date. Heat along only is for a room that should never start the boiler itself (a hallway, a cellar): it keeps its target and its valves open for it, so it warms while the boiler runs for other rooms. See Heat along only.
3. Under Temperature sources, choose the Bluetooth sensor. Up to four sources in order: the first fresh one leads, the others are fallback.
4. Set the Temperature without a week program (°C) (for example 19 °C) and the room's Minimum and Maximum.
5. Turn on Use a week program. Choose a template under Start from a template, set the Comfort, Eco and Night temperatures, and adjust the blocks per day (up to six switch times per day). Each temperature holds until the next switch time.
6. Choose Save rooms.
7. Then check the Water temperature limits on the Home page and choose Save limits after a change (default 30–60 °C; the maximum can be set up to 80 °C). Floor heating fed directly without a mixing valve usually needs at most 45–50 °C. The page shows your boiler's own maximum heating temperature; the E32 never asks for more than that. Lowest water temperature: automatic is on by default: the E32 never asks for less than 30 °C and raises the lowest by itself where it learned that your boiler needs it (the lowest temperature your boiler starts at, and the steady-burn floor with Smart warm-up on). Turn it off to set your own lowest value; the E32 then uses exactly that value and never asks for cooler water, also when weather compensation would. The line under the fields says what the E32 uses now and why: "(standard)", "(set by you)" or "(learned)". Home Assistant has the same tick on the dashboard's Settings → Heating and boiler → Water temperature limits (the lowest value waits while the tick is on), with the value in effect under it. After the update from an older version, a lowest value of your own stays yours (the tick off); the standard 30 °C becomes automatic.

The E32 stores large week programs in a compact form, so 8 rooms with four switch times a day fit. A plan that is still too large is refused with a message, and nothing changes.

Check it #

On the Rooms page the room shows its temperature, its target and where the target comes from (for example "Target temperature from the week program"), and the calculated boiler request. The status reads "Measured". The Overview shows the same rooms at a glance. Each room's card there says in one line why the room heats or not, in the same words as Home Assistant: off, window open, no reading, hot water, boiler rest, holiday, away, Smart warm-up heating early, warm enough. This works without Home Assistant too.

Home Assistant: the details #

Connecting Home Assistant #

The installation guide describes each step in detail. In short:

You need Home Assistant 2026.10.0 or newer (the automatic tests run against 2026.10.0, 2026.10.4, 2026.11.0 and 2026.11.1; it is in use on 2026.11.x).

1. Set up Home Assistant's MQTT integration with a local MQTT broker, and enter the same broker under E32 System → Settings → Home Assistant: tick Connect to the MQTT broker and enter a broker user name and password. The E32 does not connect to Home Assistant through a broker without a login. Until you connect the E32 in step 3 the page says (E32 1.4.5) that the E32 sends nothing over MQTT without the Home Assistant link; step 3 switches the link on. When it links an E32 whose MQTT base was different, Home Assistant also clears the old firmware's "OpenThermostat 1.0.0" entities under that base (1.4.5).
2. Install the OpenThermostat integration package, restart Home Assistant and add OpenThermostat under Settings → Devices & services. You do not need to add a room in Home Assistant first.
3. Choose Configure → E32 connection and enter the E32 address and password. The address may be an IP address or a local name such as http://openthermostat-a1b2c3.local, http://e32.fritz.box or http://e32.home.arpa. Home Assistant switches the E32's MQTT connection to Home Assistant and waits for its first report (up to two minutes); the E32 may restart once.
4. From then on, rooms are managed in Home Assistant on the dashboard's Settings → Rooms (without the dashboard: Configure → Rooms). Your existing E32 rooms appear there unchanged.

Installed with an earlier integration version that needed a starter room in Home Assistant? That room is no longer used. Remove it with Settings → System → Repairs → "Old Home Assistant room no longer used" (or the dashboard's Settings → Installation → Remove old Home Assistant rooms; without the dashboard Configure → Advanced and diagnostics → Remove old Home Assistant rooms); see the installation guide.

Old Home Assistant rooms #

Rooms set up in Home Assistant itself (the way before the E32 kept its own rooms) are called old Home Assistant rooms everywhere. Their settings appear only while such a room exists:

• On the dashboard's Settings → Installation, while an old room is left: Status of the room setup (the checks, read only) and, under Maintenance, Remove old Home Assistant rooms.
• An installation that is connected to the E32 without the dashboard keeps its everyday menu. Under Advanced and diagnostics it shows, while an old room is left, Check the old rooms (what is saved and what the valves report), Water temperature limits of the old rooms and Remove old Home Assistant rooms, which hands the rooms over to the E32 and removes them from Home Assistant.
• An installation that was never connected to the E32 and still has old rooms starts with Old Home Assistant rooms (change or remove one) and Heating of the old rooms. Without an old room it starts like a new installation, with E32 connection: connect the E32 and make the rooms there, under Rooms.

The room devices #

Every E32 room is a device in Home Assistant. Its model says what the room is: "Room on the E32: radiators" or "Room on the E32: floor heating" (Dutch "Ruimte op de E32: radiatoren" / "vloerverwarming"), and its software version is the E32's firmware version. When you rename a room or switch it between radiators and floor heating, the device follows as soon as Home Assistant hears it from the E32 (within seconds); after a firmware update every room device shows the new version. A name you gave the device yourself stays. The model is written in Home Assistant's language; before the E32 has said which kind of room it is (a first start) it reads "Room on the E32".

Each room also has its own group on the integration page. Deleting that group does not remove the room: while the room is in the E32 room plan, the group comes back with the same names, areas and history (the log says so). To remove a room, open it on the dashboard's Settings → Rooms and choose Remove room (or in the room editor: Edit or remove a room).

The diagnostics download #

Settings → Devices & services → OpenThermostat → ⋮ → Download diagnostics gives one file for help with a problem. It never contains passwords, keys, addresses or Wi-Fi names. Besides the E32 version, the room plan, the last reports of the E32, the energy inputs and the entity counts it holds, read out as figures:

• setting_devices: per room its setting device, whether Home Assistant writes the week program's temperature to it (a setting device and a week program), the device's own target, the temperature the E32 wants shown now, the last write and how long ago, a knob change on its way to the E32, and how often the device changed its target by itself (its own schedule). A room without a setting device names the thermostat that could be one.
• learned_store: what the E32 could keep of what it learned: the rooms restored at its last start, the rooms and parts in its last save, free storage, whether the last save left rooms out, the "Known about your house" figure now and before the last E32 restart, and the Repairs items about it.

Repairs in Home Assistant #

Settings → System → Repairs shows an item only when something is broken or waits for your decision. Most items go by themselves once the cause is gone; an item with Fix asks for one step. Information never appears there: what changed, a design fact or an advice is in the help text of the form or in this guide (since 1.4, for example, a room with one temperature source is explained at the room's temperature sources). This is the complete list.

A room with a Home Assistant thermostat and a Bluetooth fallback #

This example uses an existing thermostat in Home Assistant as the main source and the paired Bluetooth thermometer as fallback.

1. Open the OpenThermostat dashboard, Settings → Rooms, and add a room or choose an existing one. (Without the dashboard: Settings → Devices & services → OpenThermostat → Configure → Rooms.) The fields below are those of Configure's room form; on the Settings tab the same fields stand in the room's sections (Temperature, Week program, Windows and doors, Persons).
2. Fill in the fields:

   • Temperature sources from Home Assistant: your thermostat's climate entity or a temperature sensor. Sources in °C, °F or K are converted to °C for the E32.

   • Bluetooth sensors on the E32: the thermometer.

   • Use the Bluetooth sensors first: off, so the HA source leads and the Bluetooth sensor is the fallback.

   • Setting device (optional): your thermostat, if you want to turn the room up or down on it. Home Assistant keeps it at the room's temperature (both ways); see Week program and setting device. Leave it empty to use the room's own thermostat in Home Assistant.

   • Temperature without a week program: for example 19 °C.

   • Week program on the E32: the form starts with the "Workdays and weekend" template. Keep it and adjust it in the visual planner (on the OpenThermostat dashboard: Settings → Rooms → the room → Week program), or type one line per group of days, for example

     mon-fri: 06:30 20.5; 22:30 18
     sat-sun: 08:00 20.5; 23:00 18
     

     A line without days applies to every day. Up to six switch times per day.

   • Temperature limits (folded section): the lowest and highest target this room may get.

   • Windows and doors and Persons (folded sections, optional): see Windows and doors and Away: the whole house and single rooms.

3. Choose Submit. Home Assistant forwards the selected entities to the E32 on every change and every five minutes. When the E32 comes back after an outage or a quick restart, all of them are sent again at once. A source that has not reported for 3 hours (a sensor that froze, a thermostat that went offline) is not sent again as if it were fresh; the E32 then treats it as lost and uses another source of the room. If you rename a source in Home Assistant, the room follows it; if it is removed, a repair Choose a new temperature source for ... appears after 10 minutes.

The E32 in turn reports to Home Assistant calmly, in small messages: a room's temperature (from 0.1 °C), the requested water temperature (from 1 °C) and the boiler (water to heating and back from 0.5 °C, burner power from 5 %, burner, hot water and faults at once) when they really change, at most every 10 seconds and otherwise every 5 minutes; other boiler values at most once a minute; what it learned every 15 minutes. A room's new target, or a new reason for it (override, away, an open window), goes out within about 2 seconds of the E32 taking it at its next control step (every 10 seconds). A target you change in Home Assistant, on a thermostat or in the week program therefore shows on the E32 and back in Home Assistant within about 12 seconds, usually sooner. The values are kept by the MQTT broker, so a restarted Home Assistant shows them at once. They only become unavailable when the E32 reports itself offline or about 3 minutes pass without its heartbeat.

With Home Assistant in °F, the editor shows and accepts °F; the plan on the E32 stays in °C.

To test the fallback, temporarily disable the thermostat's integration in Home Assistant. After its value expires, the room status changes to "Fallback source" and the Bluetooth sensor leads.

The E32 Rooms page once Home Assistant is linked #

The page then shows the rooms read-only and says "Managed in Home Assistant". Edit here anyway unlocks editing on the E32 for the current browser session. After about ten minutes without contact the page says "Home Assistant is not reachable — you can change rooms here." Every saved change goes to the same plan, and Home Assistant shows it too. The plan carries a revision number: if Home Assistant changed it in the meantime, the E32 refuses your save, reloads the plan and asks you to make your change again. Nothing is overwritten silently.

What happens when Home Assistant is offline #

• Room temperatures from Home Assistant entities stop arriving. The next fresh source in the room's list takes over, for example a Bluetooth sensor the E32 receives itself. The room card shows which source leads.
• Without a target from Home Assistant, the room follows its week program on the E32. Without a week program (or without a valid clock) it keeps its Temperature without a week program.
• If no source of a room delivers a usable reading, the room keeps its last value for 30 minutes and then stops asking for heat.

Rooms: changes, windows, away and holidays #

Temporary changes, open windows and away #

These work on top of the room plan and never change it. They only change a room's target: the water temperature limits, the boiler's own limit and frost protection stay as they are. During the trial run they are computed and shown, like everything else.

• A manual change (the temperature control on the E32 overview page, or the room's thermostat in Home Assistant): Boost heats to the room's maximum for an hour. A temperature you set yourself follows one rule, with E32 1.4.2:

  • With a week program it lasts until the next switch time of the program (for example 22:00), however far away that is, also over a quiet weekend. The E32 ends it itself and the room returns to its week program, also after a restart. After a restart the E32 waits for a valid clock before it applies a stored change; until then the room follows its plan. A change made while the E32 has no valid clock lasts 2 hours and is not kept across a restart.
  • Without a week program it becomes the room's Temperature without a week program (Heat along up to on a room that heats along), for good. The old value is gone. A reset time can set it again (see Reset times).
  • It never changes the room's state: an Off room stays Off, a room on Heat along only stays on it.
  • It ends when a holiday or Away begins later, and when the room is switched off. A room whose Off until has passed is on again.
  • With E32 1.4.1 (Home Assistant 1.4.2 still works with it) a change "until the next switch time" still lasts at most 24 hours.

• Windows and doors (Home Assistant: Settings → Rooms → the room → Windows and doors): see Windows and doors below.

• House mode (E32: Home; Home Assistant: Settings → House → House mode and holiday, or the House mode control on the E32 device and on the dashboard):

  • Automatic: the people of the house decide. Choose them under Settings → House → Presence and away temperature (several person entities, or a group, zone or switch). When everyone has been away for the away delay (15 minutes by default), every room is at most the away temperature. Someone home, or someone whose place is not known, keeps the house warm. A room can have persons of its own (the room editor in Home Assistant, section Persons → Persons of this room, for example a bedroom and its occupants). Such a room goes to its own away temperature (or the house one) when all of its persons have been away for the same delay, also while others are home. A room without persons of its own follows the house. The E32's room card shows what Home Assistant reports for the room's persons. See Away: the whole house and single rooms.
  • At home: the week programs always, also when everyone is away (guests, a babysitter).
  • Away: every room is at most the away temperature until you switch back.
  • Holiday: away from now until a date and time, at the Temperature on holiday (Home Assistant: Holiday ends in Settings → House → House mode and holiday, or the Holiday until entity; E32 Home page: Away until, then Start holiday). Choosing Holiday in the list in Home Assistant starts the next planned holiday; without a planned holiday it tells you to plan one or to use Holiday ends. Afterwards the house returns to Automatic. To plan holidays ahead, see the holiday planner. The E32 starts warming up early enough to be at the week program's temperature when you are back (from what it learned, else 45 minutes per °C for radiators and 2 hours per °C for floor heating).
  • Summer (E32 1.4.1 and newer): the heating stays off until you switch this off; hot water and frost protection stay. See summer mode.

  The away temperature is Temperature when nobody is home (15 °C by default): on the E32 device, on the E32 Home page and in Settings → House → Presence and away temperature, all three the same setting. Frost protection always stays on. On holiday the Temperature on holiday counts instead (see the holiday planner).

In Home Assistant each E32 room has a thermostat: current temperature, target, mode Auto (week program), Heat (a manual change) or Off (the room is inactive in the plan), and the presets Comfort, Eco, Night and Boost. Away is the house mode, not a preset of one room. Comfort, Eco and Night are the room's three week-program levels, the same as in the week planner, where each is set on its own; a room without a week program uses the Room defaults of Settings → House (the thermostat's attribute "Comfort, Eco and Night from" says which). A new target on the thermostat is a manual change: with a week program it lasts until the next switch time; without one it becomes the room's temperature without a week program, for good. It never changes the room's state.

Windows and doors #

An open window or door pauses a room: it drops to frost protection (only heats below 8 °C) and asks for no heat. When all its windows and doors are closed again, it follows its program at once. Any sensor works that Home Assistant knows as a window, door, opening or garage door sensor, of any brand (Zigbee, Z-Wave, Shelly, Bluetooth, a template).

Choose them per room in Home Assistant: Settings → Rooms → the room → Windows and doors (up to 8 per room, windows and doors together; after you choose one, an empty field appears below it for the next):

• Window contacts and Pause after (windows): the room pauses when a window has been open this long. Default 2 minutes, so airing briefly does not pause the room.
• Door contacts and Pause after (doors) (1.1.0): for doors you open often for a moment, such as the front door or the door to the garden for the dog. The room pauses only when a door has been open this long. Default 5 minutes.

A sensor is a window or a door, not both. Every contact you chose before 1.1.0 is a window, so nothing changes until you move a door to Door contacts. The defaults for rooms without their own delays are under Settings → House → Room defaults (Pause after a window opens, Pause after a door opens).

The delays count from the moment the window or door opened. The E32 keeps them, so a restart of Home Assistant does not start them again; after a restart of the E32 they start again when Home Assistant reports the open window or door (within a few seconds once it is connected). If Home Assistant stops reporting, the E32 forgets an open window or door after 15 minutes and the room heats normally.

What you see: the room card on the dashboard and the room's Reason say "Paused: Front door open since 14:05" (while the delay runs: "Front door open: the room pauses soon"; without a contact Home Assistant can name, "A door is open: the room pauses soon"). On the E32 overview the room says "Paused: a door is open" or "Paused: a window is open", and the room's Windows and doors block on the E32 Rooms page says which is open. The contacts themselves are chosen in Home Assistant.

With E32 firmware 1.0.0 (before 1.1.0) the doors work too, with one difference: the E32 then knows only "a window or door is open". Home Assistant sends the door delay while only doors are open and the window delay as soon as a window is open; a window opened while a door is already open can then pause the room sooner than 2 minutes. The E32 pages then say "a window or door".

Away: the whole house and single rooms #

OpenThermostat turns rooms down while people are out. It does this for the whole house, and for single rooms.

The three rules

1. Everyone is away. Every room goes to the house away temperature (Temperature when nobody is home, 15 °C by default). The house mode Away does the same. On Holiday every room goes to the Temperature on holiday instead, which is the away temperature until you set another.
2. Only the people of one room are away. A room can have its own people. When all of them are away, that room goes to its own away temperature, even while others are home. A room with two people only cools down when both are out.
3. A room without its own people follows the house. It only cools down when everyone is away (rule 1).

A room with its own people but without its own away temperature uses the house away temperature in rule 2.

Examples (house away temperature 17 °C, living room 21 °C)

• Anna's study. The study has one person: Anna. Its own away temperature is 16 °C. Anna goes out and Ben stays home. The study goes to 16 °C. The living room has no people of its own, so it stays at 21 °C.
• Both out. Anna and Ben both leave, so everyone is away. Every room goes to the house value of 17 °C, the study too. When everyone is out, the house value counts for every room.
• A room for two. The bedroom belongs to Anna and Ben. Anna leaves, Ben is still home: the bedroom stays warm. It cools down only when both are out.

Good to know

• The away temperature is an upper limit. A room whose program is already cooler stays cooler.
• At home ignores who is home. No room cools down, also when everyone is out (for guests or a babysitter).
• An open window still pauses the room. That always comes first.
• Frost protection always stays on: any room below 8 °C asks for heat.
• A person counts as away only after the away delay (15 minutes by default). Someone whose place is not known counts as home: in doubt, the room stays warm.

Coming home

When one of the room's people comes back, the room follows its week program again at once and starts to heat. The E32 cannot know in advance when you come back, so the room needs some time: roughly 45 minutes per °C with radiators and about 2 hours per °C with floor heating. A floor-heated room that went 4 °C down can need most of a working day. For floor heating, choose an own away temperature only 1 or 2 °C below the normal temperature.

A Holiday has an end date. Then the E32 starts warming up early enough to be warm when you are back (see the holiday planner).

How to set it up (in Home Assistant)

1. Choose who lives in the house: the dashboard's Settings → House → Presence and away temperature (without the dashboard: Configure → House → Presence and away temperature).
2. Give a room its own people: Settings → Rooms → the room → Persons → Persons of this room (without the dashboard: Configure → Rooms → Edit or remove a room → the room → section Persons).
3. In the same section, fill in Temperature when this room's people are away, for example 16 °C. Leave it empty to use the house away temperature.
4. Choose Submit.

The E32 Rooms page shows the same value in the room's Persons block, and you can change it there too, also without Home Assistant. The people themselves are chosen in Home Assistant, because Home Assistant knows where they are.

The value is stored on the E32 with the room. It is part of the E32's settings backup and comes back with a restore.

Where you see it

• The E32 Overview, in the room's reason line: "Away: nobody of this room is home (16 °C)" or "Away: everyone is away (17 °C)". On holiday the line says "Holiday until …" with the temperature on holiday.
• The E32 Rooms page, in the room's Persons block.
• The room's thermostat in Home Assistant shows the lower target. Its attributes away_reason (room_persons, everyone or house_mode) and own_away_temperature tell why.

An E32 on old firmware has no away temperature per room. Home Assistant and the E32 page then do not show the field, and every room uses the house value.

Holiday planner #

Plan holidays ahead, up to 8, each with a start and an end (back home). A holiday starts and ends by itself. During it every room stays at most the Temperature on holiday (5–25 °C); until you set one, that is the away temperature (Temperature when nobody is home). Frost protection always stays on. The E32 warms the rooms up before the end, so the house is warm when you are back, and afterwards the house mode is what it was before the holiday.

In Home Assistant: Settings → House → House mode and holiday. The screen lists the planned holidays and has:

• Plan a holiday: choose Starts and Ends (back home). A start in the past starts the holiday now; the end is at most a year ahead. Holidays that overlap become one.
• Change or remove a holiday (shown while a holiday is planned): choose the holiday, change its times, or tick Remove this holiday.
• Temperature on holiday: the same setting as the number Temperature on holiday on the E32 device and on the E32's Home page.
• House mode: the house mode itself, as before.

While a holiday runs, the screen also has Stop holiday: it ends the holiday now and the house goes back to its mode. The Overview tab of the dashboard shows the next holiday ("Holiday from 20 Dec to 3 Jan", and "On holiday until 3 Jan" while it runs).

On the E32: the Home page has a block Holidays: the list with Change and Remove, Add a holiday (From, Until, Save holiday), Temperature on holiday (°C) with Save, and, while a holiday runs, "On holiday until …" with Stop holiday. Home Assistant and the E32 page edit the same list.

Good to know:

• Saving a holiday needs the E32's clock. Without a valid time the E32 says "The E32 clock is not set yet, so a holiday date cannot be used. Try again in a minute."
• Choosing Automatic, At home or Away as the house mode ends a running holiday; holidays planned for later stay.
• A holiday that is over leaves the list by itself.
• Planned holidays and the temperature on holiday are part of the E32's settings backup. A restore leaves out holidays that are already over.

Summer mode #

The fifth house mode, for the months without heating: "Summer mode: the heating stays off until you switch this off; hot water and frost protection stay." It has no end date and no temperature. It needs E32 firmware 1.4.1 or newer; with older firmware Home Assistant does not offer it.

Switch it on: the House mode control (the Overview's Home or away, the E32 device) or Settings → House → House mode and holiday. Switch it off: choose the mode you had before (the house mode control shows it as its attribute previous_mode; the banner at the top of the dashboard switches back to it). A holiday that was planned stays planned; one that was running continues while its end is ahead.

What it does:

• No room gets more than its frost limit: week programs, reset times, manual changes, Smart warm-up, Away and Holiday do not apply. A room that is off stays off. Frost protection works as always.
• Hot water is untouched: the boiler makes it as always.
• Every Monday at 12:00 the E32 opens the valves it drives by position fully and runs its circuit pumps for one minute, so they do not stick. The house mode control shows the last time (attribute summer_exercise). Without a valid clock at that moment the exercise is shortened or skipped.
• A change on a setting device or a valve is put back within a minute.
• The learning (arrival times, warm-up per room, the self-tuning and the scoreboard's verdict) skips summer days; the day figures are still counted.

On the dashboard: a banner starts every tab ("Summer mode: the heating stays off until you switch this off; hot water and frost protection stay.") with the button Switch summer mode off, which asks once; the room cards say Summer in grey instead of their state.

In Home Assistant: every room thermostat is Off with the attribute reason: summer. Setting a temperature, a mode, a preset, a manual change or away on it is refused with "Summer mode is on: switch it off first." and nothing is sent to the E32. Each room's Reason says Summer.

The season hint. The E32 watches the outdoor temperature (if you gave it one). After five days in a row with an average of 17 °C or more, while not in summer, it asks "Five days above 17 °C outside on average. Switch summer mode on?"; in summer, after three days of 12 °C or less, "It is getting colder. Switch summer mode off?". It never switches by itself. Home Assistant shows the question as the house message Season (Settings → Notifications → Which messages → The house → Maintenance; ticked once for you in 1.4.1 when your house messages were already on), once per hint: on a phone with the Home Assistant app with the buttons Switch summer mode on (or off) and Not now, elsewhere as the sentence alone. The question goes once you answer it (also by switching summer mode yourself) or after seven days, and the same hint does not come back. The house mode control shows it while it stands (attribute season_hint), and the house card on the Overview shows it as a grey row with one button. It is never a Repairs item.

On the E32's own pages (without Home Assistant): the Home page has Summer as a fifth button next to Automatic, At home, Away and Holiday, and the Overview says why no room heats while it is on.

Week program and setting device #

A room runs its own week program on the E32, also without Home Assistant. A new room starts with "Workdays and weekend" (about 20 °C, 18 °C during the day on workdays, 16 °C at night); change it in the week planner. A room without a program keeps its Temperature without a week program: leave the program empty (on the room's Week program screen, switch off Start with the standard week program). Since 1.4 an empty field stays empty and the screen shows the program the room really has; before, Home Assistant filled in "Workdays and weekend" when the room was saved. After a save the list of rooms says what the program now is. The planner works with three levels, Comfort, Eco and Night; set each temperature on its own (equal values and any order are allowed) and paint the days with them. Copy… copies a day, Undo takes back a step, and Advanced: edit as text shows the program as text. A room without a program is a choice, not a fault: Repairs does not ask to give it one (since 1.4). A room's reset times are markers above its days: an arrow down at the time, with the value beside it ("14°", "on", "heat along" or "off"; hold the pointer on it for the whole sentence). + Reset time adds one on the day you last touched, at 22:00 or the first free quarter after it. Drag a marker to move it in steps of 15 minutes (on every day of that reset time), or with the keyboard the arrow keys; tap it for its card: the time (as Home Assistant shows times), the days (Every day, Workdays), the value (Temperature in half degrees within the room's limits, On, Heat along only or Off) and Remove. Under the planner the list Reset times has the same reset times, each with change and remove, and below it the room's Smart warm-up (As the house, On or Off). Advanced: edit as text also shows the reset times as text, one per line, as in Configure's room form. Save to E32 stores the program, the reset times and Smart warm-up of the room together; when one of them was changed elsewhere since the planner opened, nothing is saved and the planner says so. The room's card on the dashboard says when the next one comes, for example "Resets at 22:00 to 14 °C".

Optionally each room has a setting device (the room editor's "Setting device" field): a thermostat or radiator valve in Home Assistant (for example a tado or a TV02), or a number with a target. Home Assistant then shows the room's temperature on that device, and when the room or the E32 changes or comes back. This works both ways, with and without a week program. Turning the device is a manual change of the room (until the next switch time with a week program, for good without one), like a change on the room's thermostat in Home Assistant or on the E32 page. A turn on an Off room only changes its temperature; the room stays Off. Home Assistant sets the device to manual itself (at most once an hour, three times) when it finds it on its own schedule. A radiator valve can be a setting device or a valve the E32 drives, not both; see one role per valve. Turn off the device's own schedule (manual mode); otherwise it changes the temperature by itself, and Repairs says so when it notices. Without a setting device the room's thermostat in Home Assistant and the E32 page set the room. Only the device you chose is ever written to, never while the room is off or paused for an open window, and at most once a minute.

The device shows the temperature the room aims for now: the program's, and also a manual change (from the room's thermostat, the E32 page or the device itself), a reset time and away or holiday. Nothing is written while the E32 does not know the time yet (just after a restart without a network): its program does not run then, and the room follows the device itself. Nothing is written to a device that is unavailable either; when it is back it gets the room's temperature, and the value it had is not taken as a turn of the knob.

Some devices (a tado, for example) report the temperature they had before once more shortly after Home Assistant sets a new one. Home Assistant remembers what the device showed just before each of its writes: that old value within 10 minutes after the write is not a manual change. The room's temperature is set again (after the minute's wait). If the device shows the old value a second time in those 10 minutes, or any other value, somebody turned it and it is a manual change as always.

What the setting device did. The room's thermostat in Home Assistant shows it under Attributes:

These values are kept until Home Assistant restarts, and come back with the next write or turn. A room without a setting device has none of them.

If setting the device fails three times in a row, Settings → System → Repairs shows "device does not take the room's temperature", with the last error. Check that the device is on and set to heat, that it takes a target temperature (a thermostat that only has a range, such as the Bosch Room thermostat II through Zigbee2MQTT, gets its lower value), and that the entity still exists. The message goes away by itself as soon as setting the device works again, or when the room gets another setting device.

Without Home Assistant the E32 keeps running the program; changes on the device are not seen until Home Assistant is back, and then the program's temperature is shown on the device again.

A setting device is a real device, also during the trial run: a radiator valve then follows the week program, and a thermostat that controls your boiler (such as a tado) gets the program's temperature, so the program decides through it when the boiler heats. Leave the field empty if you only want to watch first.

Bluetooth window sensors (for example Shelly BLU Door/Window) paired on the E32 itself are not supported yet; connect them through Home Assistant.

Heat along only #

A room has three states: On, Heat along only and Off (with Off until for a pause that ends by itself). Set it on the E32 Rooms page (State), in Home Assistant under Settings → Rooms → the room → General (Heating), or with the room's Heating selection, for example from an automation.

Heat along only is for a room that should be warm when the heating runs, but should never start the boiler for itself: a hallway, a landing, a cellar. The room keeps its target (its week program, a manual change from the thermostat, or its Heat along up to temperature). Its radiator valves get that target, so they open while the room is cooler. But the room never asks the boiler for heat, and its shortfall never raises the water temperature. It warms while the boiler runs for the other rooms. An open window still pauses it.

Frost protection stays. Below 8 °C a room on Heat along only asks for heat after all, only to keep it above 8 °C: from 7.8 °C until it is back at 8.2 °C, with 8 °C as its target for the boiler. Its card and Reason sensor then say "Heats along; below 8 °C it asks for heat".

Off and on again. Switch a room on Heat along only off (Off, Off until, or the thermostat's Off in Home Assistant), and it remembers. When it comes on again, through the end of Off until or the thermostat's Heat or Auto mode in Home Assistant, it heats along only again, not On. The Rooms page says so on such a room ("Off. Switched on again, it heats along only."); there you choose its state yourself. Choosing On or Heat along only clears the memory. The E32 keeps it in the plan as "follow_when_on": true on a room that is off; firmware before 1.3 ignores it, so for it the room is off.

It takes no part in learning the warm-up times (Smart warm-up, the morning check) and is no part of the heating plan, because it takes heat without asking for it. The E32 still keeps its measurements. Its card says "Heats along" in place of "Requesting heat" or "No request", and its Reason sensor says "Heats along: it never asks for heat itself".

From the room's thermostat (1.4). The room's thermostat in Home Assistant has the preset Heat along only beside Comfort, Eco, Night and Boost, so a card, a voice assistant or an automation can set all three states. Choosing it sets the room's state, like the Heating selection, also from Off; the preset shows Heat along only while the room is on it. Since 1.4.2 setting a temperature never changes the state: it is a manual change (see Temporary changes), so the room stays on Heat along only. What the other controls do:

• Heat mode: from Off the room goes back to the state it had (On, or Heat along only), without a new temperature. Otherwise the current target becomes a manual change. Heat along only stays Heat along only.
• Auto and turning the thermostat on: from Off the room goes back to its state, and a running manual change ends.
• Comfort, Eco and Night are a manual change with the room's planner level. Boost keeps the state, also on Heat along only (the preset then reads Boost while it runs).
• The preset "none" from Heat along only is the way back to On.
• A room that is Off: with a week program the thermostat refuses a temperature ("This room is off. Switch it on first."); without one the temperature becomes the room's temperature without a week program and the room stays Off. While the room is Off the thermostat shows its stored temperature.

The action Temporary temperature for a room is the same manual change; it is refused on an Off room, and "until the next switch time" is refused on a room without a week program. Switching the setting device on the wall off or on does not change the room's state.

Heat along only needs E32 firmware 1.3 or later; Home Assistant offers it (also as the preset) only to such an E32.

An Off room still shows its temperature (E32 firmware 1.4). An Off room asks for no heat at all, and its valves only protect against frost (8 °C). The E32 keeps reading its sensors and reports the temperature and where it comes from, without a target. The room's card on the E32, the Overview ("Now 17.2 °C"), the room's thermostat and card in Home Assistant, its page on the Rooms tab (one line: "Off · 17.2 °C (Bluetooth sensor)") and the history show it, without gaps. Older firmware leaves them empty.

Reset times #

A reset time sets a room back at a fixed time: on that moment any manual change ends and the room takes this value; the E32 does not work towards it. It is a safety net, not a goal. Set them in the week planner (with the dashboard: Settings → Rooms → the room → Week program; + Reset time, then drag or tap the marker, see week program), on the E32 Rooms page (block Reset times, under the week program), or as text in Configure's room form (below). The rules:

1. When. A time (whole minutes) and one or more days, Monday to Sunday, in the E32's local time with summer and winter time, like the week program. At most four per room, never two on the same day and time.
2. What it does. Every manual change of the room ends: Boost, a temperature you set until the next switch time, also one from the setting device or Home Assistant. Then the value:
   • A temperature becomes the room's temperature. With a week program it holds until the program's next switch time; without one until the next reset time or a new manual change (which becomes the temperature without a week program). It is not stored; see 6 for a restart. It must lie within the room's minimum and maximum, in steps of 0.5 °C.
   • A state (On, Heat along only or Off) becomes the room's state, stored as if you chose it under State. On and Heat along only end Off until. Off remembers Heat along only, as in Heat along only; a room that is already Off until a later moment stays so.
3. After it the room is free: a turn of the knob or a temperature from Home Assistant is an ordinary manual change again and lasts as always.
4. No warming up towards it. Smart warm-up, the heating plan and the learning of warm-up times look only at the week program. Smart warm-up still warms the room in time for the program's next switch time, also from a reset time's temperature.
5. Order. Away, holiday and the house mode stay on top (at most their temperature), an open window still pauses the room and frost protection stays. A reset time on the same minute as a switch time of the week program wins (the switch time comes first).
6. Without a clock nothing happens, as with the week program. After a restart, or as soon as the clock is known, the E32 applies the latest reset time of the past 24 hours that it missed, unless something was changed after it (a change made after the moment survives the restart). A reset time added later never acts for a moment before it existed.
7. A room without a week program is a room with only reset times.

As text in Configure's room form (without the dashboard: Configure → Rooms → Edit or remove a room), the field Reset times (optional) takes one per line: the days, the time, the value.

The days are written as in the week program (mon, tue, … sun, ranges such as mon-fri, lists such as sat,sun; daily, or no days, is every day). The states are on, heat along and off. In Dutch: ma-vr 22:00 14, dag 23:00 meeverwarmen, aan, uit. Temperatures in your Home Assistant unit, in whole or half degrees, within the room's limits. Two reset times on the same day and time are refused before anything is sent.

Where you see them. The room's card on the E32 shows the next reset time when it comes today ("Resets at 22:00 to 14.0 °C"); while a reset time's temperature holds, the target says "Target temperature from a reset time". For Home Assistant and automations, the room status carries next_reset ({"utc", "temperature_c"} or {"utc", "state"}, null without one) and setpoint_source reset. In Home Assistant the week planner shows each reset time as a marker above its day and changes them there (a 1.4 planner, without that, leaves them alone when it saves); the room card on the Overview names the next one ("Resets at 22:00 to 14 °C"); the room's thermostat has the attributes next_reset (when) and next_reset_value (its temperature, or active, follow or inactive); a setting device on the wall gets the reset time's temperature; and the diagnostics download lists every room's reset times. In the room plan (GET/POST /config/heating) a room has "resets": a writer that leaves the key out keeps the room's reset times, an empty list removes them. Reset times need E32 firmware 1.4: with older firmware Home Assistant shows one sentence instead of the field and sends nothing about them, and the E32 before 1.4 ignores them, so going back to 1.3 loses them.

Learning: how the E32 tunes itself #

Warm on time (Smart warm-up) #

A time in the week program means "warm at that time": with 21 °C at 09:00 the room should be 21 °C at 09:00, not start warming then. Smart warm-up does that by itself. The E32 learns how fast each room warms up and cools down, and starts heating early enough, with the coolest water that still gets the room warm in time (cooler water lets the boiler condense, so it uses less gas). It never asks for water below the lowest or above the highest water temperature you set, nor above the boiler's own maximum, and it starts at most 8 hours ahead.

From the first morning. A room that is not learned yet does not wait for the program time. The E32 starts early at once, as an estimate: 2 hours per °C that the room is still below its coming target for floor heating, 45 minutes per °C for radiators, and at most 3 hours (floor) or 90 minutes (radiators) ahead. The pages say so: "starts at 07:40 (estimate; it learns from every morning)". The warm-up time counts as learned after one water temperature; until the coolest water is learned too, the pages say "The warm-up time is learned; the coolest water is still being learned."

It checks every morning. After each rise of the program the E32 looks at whether the room was warm at that time (within 0.1 °C of the target). A morning that was less than 10 minutes early or late teaches it nothing. Beyond that the next start moves a little at a time (E32 1.4.6): by 30 per cent of the part beyond those 10 minutes, so a room that was 40 minutes late starts 9 minutes earlier the next morning, and one that was 40 minutes early starts 9 minutes later. One morning moves the start by at most 15 minutes, and the start never ends up more than an hour away from the E32's own estimate of the warm-up time. Before 1.4.6 one morning could move it by up to half of the warm-up time, which made the start swing from day to day. A warm-up of less than 10 minutes keeps small steps (more than 10 minutes late: 10 per cent longer; more than 15 minutes early: 8 per cent shorter). A room that is not warm within 3 hours counts as 3 hours late. Only starts the E32 really made are judged. The E32 keeps the result for each room over a restart and when you reorder or rename rooms.

A restart does not cost the morning (E32 1.4.6). A judged morning is stored at once, so a power cut a minute later does not lose it. If you update or restart the E32 (the restart button, an update) before the switch time, the morning still counts when the E32 was down for at most 5 minutes, or for at most 15 minutes once the room had arrived. A longer stop in the middle of a warm-up, or a restart after the switch time, teaches it nothing from that morning.

After the switch time (E32 1.4.6). A room that is still short when its switch time comes keeps getting the water the warm-up asked for until the room is warm (the E32 counts a room as warm within 0.1 °C of its target), for at most 90 minutes after the switch time. Before 1.4.6 the water could fall back to the cooler weather-curve water at the switch time, and the room crept up the last tenths. It never asks more than the warm-up asked, and never more than the limits you set or the boiler's own maximum. It ends earlier when somebody changes the room's target by hand, when the program no longer asks for that temperature, when the room is paused (window, away, holiday, summer mode), or when the room's reading is not fresh. A restart of the E32 ends it too: the normal control then heats on.

When the start counts as learned (E32 1.4.6). Before 1.4.6 a room counted as learned after three judged mornings, whatever they were. Now the E32 looks at the last five usable mornings of each room, and the timing is learned only when four of them were within a quarter of an hour of the switch time, early or late. Until then the room is still collecting (fewer than five usable mornings) or checking (five, but not four of them within a quarter of an hour). A morning is not usable when the E32 restarted during it, when the room had more than 10 minutes of hot water in the warm-up, or when it was within 0.3 °C of the target at the switch time and arrived only by creeping up the last tenths. An unusable morning still moves the start, it only does not count as proof. A learned timing that loses its proof (fewer than five usable mornings among the last eight) is held back until five usable mornings prove it again. Only a learned timing lifts the cap on a start estimate that no learned rate backs, and "Known about your home" counts the morning check as known only then.

Within limits. All corrections together (the morning check, and the free heat of the sun and the house, which starts a warm-up later) keep a planned start within 70 to 150 per cent of the E32's own estimate of the warm-up time (one 5-minute step can add up to 4 minutes). The factor of the morning check stays between 0.7 and 1.5 (before 1.4.6: 0.5 and 2.0), and a value stored by 1.4.5 outside it is brought inside when the E32 starts. After the update to 1.4.6 every room collects usable mornings again, which takes about a week; meanwhile "Known about your home" can be lower and an estimate cap stays on a room that has no learned rate.

What to expect in the first days: the first starts are a guess, so a room can be warm a little early or late. Every morning moves the next start towards the right time, so it gets closer with each morning, and the pages tell you how it went.

What this does not do (E32 1.4.6). Warm on time is an aim, not a promise. In the simulated houses of the test bench:

• Floor heating is on time (between 15 minutes early and 5 minutes late) on 27 to 40 per cent of the mornings, radiators on 76. The warmth stored in a floor is hidden from the room sensor, so the same shortfall can wait 10 minutes one morning and over an hour the next before the room starts to rise.
• In a house with several rooms on one boiler a warm-up can still start hours too early (up to 3 hours 45 minutes), and the E32 corrects that more slowly than 1.4.5: at most a quarter of an hour a morning, never below 70 per cent of its own estimate. A stricter bound per kind of heater is written but not switched on, because it made such a house later.
• A floor whose manifold pump starts only at about 45 °C: the E32 still asks cooler water for part of the day, on the worst simulated day for 277 minutes (1.4.5: 152). The floor's working temperature is not part of this release.
• A room that has not learned how fast it warms keeps its capped first estimate until it has, so a room that needs longer is late until then. 1.4.5 lifted the cap after three mornings, good or not.

The room card on the E32 Overview, the Home page's "What the E32 has learned" and Home Assistant (the learned overview, and the attribute smart_warm_up of the room's thermostat) say what it does, for example:

• "Smart warm-up: starts at 07:20 so it is 21 °C at 09:00." (learned)
• "Smart warm-up: starts at 07:40 so it is 21 °C at 08:50 (estimate; it learns from every morning)." (an estimate)
• "Smart warm-up: heating early for 08:00 (21 °C)" (the room's reason line while it heats early)
• "Yesterday warm at 09:12 (12 min late); tomorrow 10 % earlier." (the morning check on the E32 pages. The second part says how much earlier or later than its standard the room now starts, "tomorrow 8 % later" for example; the steps build on each other, and the part is left out while the start is at its standard.) Home Assistant says what this morning changes. With an E32 1.4.6 or newer: "Yesterday warm at 09:12 (12 min late); next time it starts a little earlier (at most a quarter of an hour a morning).", and "a little later" after an early morning; a morning within 10 minutes says nothing about moving the start. With an older E32 it says "about 10 min earlier" or "a little earlier", as before. While Home Assistant has not yet read the E32's version it names no minutes.

Home Assistant says how far a room's warm-up time is (HA 1.4.6 with an E32 1.4.6 or newer). The Learning tab, the Learning card and the chip "Warm on time" under "Known about your home" show one of four states, as the E32 reports it:

• "Still learning its warm-up time. 2 of its last 3 mornings count; it needs 5 that count."
• "Adjusting its warm-up time. It has 5 mornings that count, but fewer than 4 of them are within a quarter of an hour of the switch time."
• "Learned. At least 4 of its last 5 mornings that count were within a quarter of an hour of the switch time."
• "Not learned for now.", with the reason: too few of its recent mornings counted, the correction moved a lot in one day, or the correction is at its limit. The E32 keeps watching the room.

The last mornings follow in words, oldest first: "1 h 6 min early, 3 min late (not counted), on time, not warm within 3 hours." A morning may not count, for example after a restart or with much hot water in use; Home Assistant does not say why. The chip "Warm on time" is green only when the E32 says learned. Right after the update to E32 1.4.6 every room says "No morning counts yet". With an older E32 Home Assistant shows none of this, and the chip turns green after three judged mornings, as before. The same facts are in the overview sensor's attribute rooms[].facts.lead (state, reason, mornings, clean).

The valves and the thermostat come along. While Smart warm-up heats early for a room, that room already has its coming target: with 21 °C at 17:30 and a start at 16:45, the room's target is 21 °C from 16:45. So radiator valves open for the early heat, and the thermostat in Home Assistant shows 21 °C, with the attributes warming_up_for (the program time, 17:30) and scheduled_target (21 °C). The room card and the Rooms page say "Warming up for 17:30". The morning check still judges the room against 17:30, and the boiler's request is the same as before. This happens only while the room runs its week program: a temporary target, away, a holiday or an open window decide the target as usual. A room on Heat along only or off takes no part. The coming target reaches the valves within about 10 seconds after the early start.

Per room: as the house, on or off. Not every room needs to be warm at its switch time: for a guest room or a hall it can be enough, and it saves gas, when it starts heating at the switch time. Each room has its own Smart warm-up:

• As the house (the standard choice): follows Smart warm-up of the house.
• On: this room is warm at its switch times, also when Smart warm-up of the house is off.
• Off: this room starts heating at its switch times. It gets no early start, no morning check and no part in the heating plan; its valves and thermostat get the program's target at the switch time. The end of a holiday is still warmed up for ("Warming up for your return").

Choose it in Home Assistant under Settings → Rooms → the room → Week program (under the planner), or on the E32 under Rooms, the room, Week program → Smart warm-up. Only the early start is per room: the coolest water and the boiler's limits follow the house's switch. The pages and Home Assistant say it for such a room: "Smart warm-up is off for this room: heating starts at 07:00." The room card on the dashboard shows the chip Smart warm-up on only for rooms that warm up early. The E32 keeps the choice in the room plan ("smart_warm_up": "on" or "off"; a room as the house has no key, so firmware before 1.4 treats every room as the house), and the room's status says what is in effect (smart_warm_up "on" or "off"). It needs E32 firmware 1.4 or later; Home Assistant offers it only to such an E32.

Weather compensation is on by default too: colder outside means warmer water, before the rooms cool down. (Earlier releases called it "Follow outdoor temperature" or "heating curve".) The E32 starts with a standard setting and learns your house's own from steady heating periods of three hours. The learned overview in Home Assistant says which it uses ("Weather compensation: standard for now, learning from your house (2 of 6 steady periods)" or "Weather compensation: learned for your house"); the E32 Home page says the same. The E32 can use an estimate from its house model in between, and a chart draws the line. Without an outdoor temperature (from the boiler or Home Assistant) the water temperature follows the rooms only, and the status says so. The coolest water per room is used once learned ("Coolest water: still learning from each warm-up" until then).

Water temperature in hard frost (−10 °C) says how warm the water to your heating gets when it is −10 °C outside. In milder weather the E32 picks less. Not sure? Leave it on Automatic (floor heating 40 °C, radiators 55 °C): the E32 learns it for your house. You find it in Home Assistant under Settings → Heating and boiler → Smart warm-up and weather compensation, as a selection on the E32 device, and on the E32's Home page under Heating settings → Advanced.

Both are on for every installation. An installation that had the former option "Warm on time with the coolest water" or weather compensation (then the heating curve) off (their default) has them on after the update; what you switch off yourself stays off. Switch them off under E32 Home → Heating settings → Advanced, under Settings → Heating and boiler in Home Assistant (Smart warm-up and weather compensation), or with the switches on the E32 device. Without Smart warm-up heating starts at the program time: it may be cooler for a while after each program time, and floor heating can take an hour or more.

Learning results #

Each room device in Home Assistant also has three learning sensors. With Smart warm-up on (the default, see "Warm on time" above) the E32 uses what they show once a room has been learned; switched off they are advice only. During the trial run nothing is sent to the boiler either way.

What the E32 has learned is kept when it restarts, loses power or gets a firmware update, so learning carries on where it was (it is saved every 6 hours, at midnight, before a restart or update and, since 1.4.6, as soon as a morning has been judged; a power cut loses at most the last few hours). When a save could not keep every room, or not all of what it learned about the house and the boiler, or a restart lost a large part (what it knows about your house fell by more than 30 points), Home Assistant says so under Settings → Repairs; the message goes by itself after the next complete save or once the figure is back. The E32 keeps its settings and what it learned in a small settings memory of 630 places; it always keeps enough of them free for its own settings (the room plan, the Bluetooth sensors, the connection with Home Assistant), so what it learned waits when it does not fit beside them. The message says how many places are free, how many the E32 keeps and how many what it learned needs; the E32 tries again at the next save, 6 hours later or at the next day change.

Since 1.4.4 the E32 keeps fewer places free for its own settings (usually 155 instead of about 270) because a plan save makes its own room first: it erases what it learned, and the E32 writes that again a moment later. Houses with seven or eight rooms now keep what they learned for every room. The message still only comes when what it learned really does not fit; its numbers add up (what it needs is always more than the free places beyond those it keeps).

Since 1.4.5, on a house with many rooms the E32 keeps what it learned, the scoreboard and the hot-water days in its settings memory too; when you change the plan it briefly makes room and writes them again at once. Before, the scoreboard's yesterday and the week's hot-water figures could not be written there and started from zero after a restart. What it learned still comes first: if it grows, it takes their room and they are written again within the hour. The room plan is also stored more compactly, which frees about 20 places on a seven-room E32.

Learn again #

In Home Assistant (1.4.4): a button Learn again on each room's device and Learn again: house on the E32 device (diagnostic buttons, for automations; they are created once the E32 offers the feature and then kept); on the room's screen in the settings panel the last block Learning; Learn again: house under Settings → Heating and boiler; and the text button on the room's card on the Learning tab. The card and the panel ask first ("Clear what the E32 learned for the living room? It learns again by itself; the week program stays."); the button entity itself presses at once. On an E32 older than 1.4.4 a press says to update the E32 first, and the panel and the card show nothing.

Learn again (E32 1.4.4) clears what the E32 learned for one room or for the house, and it learns again by itself. Use it after a change to your heating: other radiators, a new boiler, floor heating added, a room with a new use. It asks first ("Clear what the E32 learned for the living room? It learns again by itself; the week program stays.") and it is not needed for normal changes of a setting or a week program. Where: on the E32, the Rooms page (per room, block Learning) and the Home page (under What the E32 has learned); Home Assistant has a button for each room and one for the house. An E32 older than 1.4.4 does not offer it, so the buttons are missing.

The E32 writes the cleared state at once, so a restart does not bring the old values back. If it could not (rare: the settings memory is full), the answer says so and the clearing is written at the next save. A room starts from its start values; the tiles say what each fact still needs.

The predictions need a valid clock; the night-setback estimate also needs an outdoor temperature (from the boiler or from Home Assistant). The product device also shows hot water today (taps, keeping warm, burner time) and whether the burner switches on and off too often (information, not a fault).

Yesterday in figures #

Once the E32 has measured a day, Yesterday shows how that day went, so you can see whether the thermostat gets better. The figures are kept over a restart; whatever the E32 did not measure is left out.

In Home Assistant it is the section Yesterday on the Learning tab. Four figures stand large at the top: how many minutes early or late the first room that is switched on was warm, the burner starts per heating hour, the gas for heating and the degree days; tap one for its history. The rest follows in lines ("Bathroom: warm 12 min late · 0.3 °C too warm", "Heating time: 6.2 h · Short burner runs: 0.4 h"). It is the only Yesterday of the dashboard, so it also holds the daily summary (see Daily summary and warnings): the burner time and starts, the gas for heating and hot water and, per room, how long it asked for heat. Under it is a chart of the missed comfort per day. On the E32 it is on the Home page, under What the E32 has learned.

Each figure is also a sensor, so Home Assistant keeps its history: per room Warm on time yesterday (minutes late) (negative: early) and Above target yesterday (°C), and on the OpenThermostat device Burner starts per heating hour (yesterday), Short burner runs yesterday, Heating energy yesterday (estimate) and Heating energy per degree-day (yesterday) (kWh/°C·d). The state is yesterday's figure; they are under Diagnostic on the device page. A sensor appears the first time the E32 has a figure for it, and from then on it stays. On a day without that figure (a room that was off or away, a mild day without a figure per degree-day, a day the E32 lost in a restart) it says Unknown, with the day in its attributes, and the dashboard leaves that figure out; it never shows another day's figure. Older firmware has none.

What the E32 knows, and what it still lacks #

The E32 also learns from your boiler and your house, and it says how far it is. There is nothing to set for any of it: the E32 tunes itself and you read what it did. This section and the five that follow describe what you find on the pages; an E32 on old firmware shows none of it, and Home Assistant then leaves the new sensors unknown and the new section out.

The first thing to read is one figure, The E32 knows your house: 70 %. It says how much of what the E32 can learn about your house it has learned. Under it, in words, stands what is still missing, for example "It still has to see how fast the living room warms up". The figure rises by itself while the heating runs. It is information and changes nothing the E32 does. It is rounded down, so 100 % means nothing is missing. Only at 100 % the card says "It has learned everything it needs; it keeps checking as the seasons change"; before that it never shows 100 %, and it lists what is missing.

The room parts are the share of your active rooms. A part that does not apply counts as known: the morning check, for example, only counts rooms whose E32 week program has a rise, and only while Smart warm-up is on. The part about your boiler counts once the E32 has learned a ceiling or the boiler's own rest (see listening to the boiler), or how much heat your house takes per °C of water temperature. The last one needs your boiler's return temperature, so a boiler that reports it gets there even when it never stops by itself. Only a boiler that reports no return temperature and never stops by itself has nothing to learn here: its state stays No return temperature and the figure tops out below 100 %.

On the E32 you find the figure on the Home page under What the E32 has learned. In Home Assistant the Learning tab starts with What the E32 knows, and the sensor Known about your house on the E32 device has the percentage as its state and the missing items, as sentences, in its attributes.

Listening to the boiler #

The E32 asks your boiler for a water temperature. A boiler that reaches it (give or take a few degrees) switches its burner off by itself, rests for a while and starts again, or it burns at its lowest power while the water still climbs above the request. Both happen although a room still asks for heat: the E32 asked for more than the house takes at that moment. The E32 hears this from values every EMS boiler reports (the water temperatures, the burner, hot water and the burner power). It never reads or changes a boiler setting, and it listens only while it controls the boiler itself.

What it learns from it:

• A ceiling for the water temperature. After a request in which the boiler stopped by itself twice, the E32 takes the request minus 2 °C as the most worth asking and keeps one ceiling per outdoor temperature range (below −5 °C, −5 to 0, 0 to 5, 5 to 10, 10 to 15 and 15 °C and up). The first such request already sets a ceiling, and the pages say Learned. From then on the E32 asks no more than the ceiling near the target temperatures (see the next point), as long as Smart warm-up is on (the default). The result is cooler water and fewer burner starts. It never goes below the lowest water temperature the E32 asks of your boiler or above your highest water temperature. Not counted: the first 10 minutes of a request (the circuit is still filling), a room that is catching up on a warm-up, and anything around hot water.
• A cold morning is not slowed. The ceiling is what the house takes near its target temperatures, where the boiler's holds happen. While the room that is furthest from its target is 1 °C or more below it, the E32 asks the full water temperature, whatever the ceiling says.
• A ceiling that proves too low corrects itself. For every 6 hours of heating at or above the ceiling in which the boiler does not stop by itself, the ceiling goes up 1 °C. The season or the house may have changed.
• The boiler's own rest. After such a stop the boiler waits before it starts again (the middle value of its last eight rests, once it has seen three). A request sooner only meets a boiler that will not start yet, so the E32 keeps its own burner rest at least that long, never more than 15 minutes. When a room is more than 0.3 °C below its target the rest is not lengthened: comfort comes first. The burner rest you or the self-tuning set is not changed; the boiler's rest only lies on top of it.
• The heat your house takes. When your boiler reports the return temperature, the E32 works out from steady burns how much heat the radiators and the floor take: in kW now, and in kW per °C of water temperature above the rooms. The house model uses that figure, and it counts for the knowledge figure too.
• The water temperature at which your boiler burns steadily. At its lowest flame a boiler that is too big for the house switches itself off and on many times an hour when the water asked is cool. The E32 finds the lowest water temperature at which your boiler keeps burning (from its lowest burner power and how much heat the house takes per °C of water) and, with Smart warm-up on, asks at least that much. Slightly warmer water then means far fewer burner starts and costs at most 4 % condensing efficiency. It learns this per 2 °C of water temperature from the last weeks: what it saw more than about two weeks ago no longer counts. It also learns downwards: once a day, in a quiet hour (no warm-up, no hot water, no open window, nobody away, the rooms at their targets) and while the boiler burns well above its lowest flame, the E32 asks 2 °C cooler water for half an hour. When the boiler keeps burning and the rooms stay warm it keeps the cooler water; when the boiler switches itself off and on or a room cools down it goes back at once and tries that temperature again after a week. It never goes below your lowest water temperature.

On the E32 the Home page says it in one sentence under What the E32 has learned, for example "Your boiler holds about 43 °C and rests 6 min; near the target the E32 asks at most 41 °C." (The ceiling it names holds near the target temperatures; a room that is 1 °C or more below its target gets more. With Smart warm-up off the sentence says what the E32 would ask.) While the boiler is still listening but the heat per °C is already known, the sentence says that figure instead: "Your boiler has not held a water temperature by itself yet; every degree the water is warmer than the rooms gives your house about 0.3 kW. The E32 keeps listening." Home Assistant shows the same on the Learning tab, under House and boiler, as tiles (the highest water, the rest, where the boiler burns steadily and where it starts heating), and has the sensor Boiler response on the E32 device. Since 1.4.5 the E32's Home page shows House and boiler in the same words and figures: the learned water line ("Learned for your house: the water gets about 0.62 °C warmer for every degree colder outside.", or "Estimated from your house: ..." and "The standard line for now: ..." while it is still learning), small tiles for the highest water at the outdoor temperature of the moment, where the boiler burns steadily from and where it starts heating from (only the ones it knows), and, when the lowest water temperature decides, the note "The lowest water temperature decides here: weather compensation would ask for 38 °C, but your boiler burns steadily only from about 49 °C water, so the E32 asks for 49 °C." The water temperature at which the boiler burns steadily stands on both, with what the daily try did last: "The E32 tried 2 °C lower water (47 °C) yesterday and kept it: the boiler burnt steadily there." (or that it went back, and why; while a try runs: "The E32 is trying 47 °C water for half an hour ..."). Under the chart Water temperature by outdoor temperature Home Assistant (and, since 1.4.5, the E32 page) adds "The lowest water temperature decides here: ..." while that temperature is above what weather compensation would ask. Its state is:

The attributes of the sensor give how often the boiler held its temperature today, its rest, the ceiling it learned for this outdoor temperature, the heat the house takes (kW) and the kW per °C of water temperature.

The house model and Weather compensation #

From how fast the rooms warm up and cool down, or else from the gas used per degree of cold, the E32 works out two figures for the house: how much heat it loses per degree colder outside, and how much heat the radiators and the floor give per degree of water temperature (taken from the boiler's measurement above when there is one). Their ratio is the steepness of the Weather compensation line: how much warmer the water must be for every degree colder outside.

Weather compensation learns that line from steady heating periods of three hours and needs six of them, which can take weeks in a mild autumn. Until then the E32 uses the house model's estimate instead of the standard line, when it has one (from two rooms whose heat loss is known, or from three days with a gas figure and degree-days). It never makes the line less than half as steep as the standard one, because an estimate must not leave rooms cold. When the six periods are in, what it measured replaces the estimate. The pages say which line is in use: "Weather compensation: estimated from your house for now, learning more (2 of 6 steady periods)". The model is worked out again every hour from what the E32 has learned.

Yesterday against your usual days #

Every day the E32 compares yesterday with the usual days of your own house, not with other houses. It keeps a usual value for four figures: gas for heating per degree of cold, burner starts per heating hour, heating hours per degree of cold and, per room, the warm-up minutes per °C. The usual value is a running average over your days; the first five days are averaged. From the fifth day on, yesterday is judged against it before it is added to it. A figure that is more than 30 % away from usual (and by more than a small minimum) gets one sentence, with what can cause it:

At most four sentences stay. They describe yesterday only: every new day replaces them, and a day with less than an hour of heating leaves none and is not counted in the usual values. A mild day or a day with too little data is not judged. This is information. It is never a Heating problem, never a Repair, and you do not need to do anything.

On the E32 you find the sentences on the Home page under What the E32 has learned, under Yesterday compared with usual. In Home Assistant each one is a notification (dismiss it and it stays dismissed until the sentence changes) and the list is on the Learning tab, under Yesterday, as Noticed.

Free heat from sun, cooking and people #

Sun through the windows, cooking and people warm a room without the boiler. If Smart warm-up ignored that, it would start too early and the room would end up warmer than its target. The E32 learns it per room and per part of the day (six parts of four hours, from midnight). It looks at stretches of at least half an hour in which no heat reached the room (after the radiators or the floor stopped giving heat: 30 minutes for radiators, 2 hours for a floor) and sees whether the room still rose by 0.2 °C or more. That rise joins the average of that part of the day; a flat or falling stretch counts as zero. A stretch in which it was warmer outside than inside is not judged.

From five stretches in a part of the day the E32 uses the number: a warm-up that falls in that part of the day starts later, its lead shrinking by the share of the warm-up rate that comes for free, but never to less than half of the usual lead. The morning check still judges every start, so a wrong guess is corrected the usual way: a room that is late gets an earlier start next time. A room that never warms up by itself shows nothing and keeps its lead.

The room's learned details say it in words, for example "In the afternoon this room warms up by itself, about 0.4 °C per hour (sun, cooking or people)" and, when it changes a start, "Smart warm-up now starts 20 min later for it, so it does not heat what comes for free." The E32 Home page always shows them, under What the E32 has learned. Home Assistant shows them, per room as the fourth fact of the room's card on the Learning tab, when the E32's report for that room has room for them.

The chart: water temperature by outdoor temperature #

Water temperature by outdoor temperature shows how warm the water to your heating gets at each outdoor temperature:

• the standard line (dashed) is what Weather compensation starts with; it follows from the Water temperature in hard frost (−10 °C);
• the line learned for your house (solid) appears once the E32 has learned the line, or estimated it from the house model. The further below the standard line, the cooler water your house needs;
• Now marks today's outdoor temperature and what the E32 asks at it, and the point at −10 °C shows the water temperature in hard frost.

The chart stays between your lowest and highest water temperature. Show the values lists the same as a table. With Weather compensation switched off the chart shows what it would ask.

On the E32 it is on the Home page under Heating settings, in the water temperature block. In Home Assistant it has its own part on the Learning tab, and you can add the card to a dashboard of your own (custom:openthermostat-heating-curve; show_name: false leaves out its title).

The heating plan #

With firmware that plans the heating, the E32 keeps a model of each room beside the heating. It predicts the room 1, 3 and 6 hours ahead and checks itself against what really happens. What it learned says per room how far it is: "The E32 is collecting readings for a model of Living room", "The E32 is checking its predictions for Living room (2 of 3 days good)", "The E32 trusts its model of Living room: heat loss 0.09 kW per degree, the room needs about 3.1 hours per degree at 50 °C water", or, after a worse spell, "...went back to its last good model and checks it again". Until you confirm, this is only a check.

The E32 also makes a plan for the next 24 hours and checks it the same way. The sensor Heating plan on the E32 device shows when it plans to start heating next. While nothing is to start it says so in a few words (since 1.4.6): "Not planning (still learning)", "Not planning (checking its plans)", "Not planning (ready for your confirmation)", "Not planning (checking again)", "Planning (nothing to start)", "Not planning", or "Waiting for the E32" while Home Assistant hears nothing from it; it is never Unknown or Unavailable. Its attributes, and the dashboard's Today's plan (tab Learning), show:

• how far the planner is, in the same line as the E32's Home page: collecting, checking ("3 of 7 days, 2 of 5 mornings predicted within 20 minutes"), ready for your confirmation, planning (or planning but heating as before for a moment, with the reason), or back to checking after a worse spell;
• why it plans what it plans, for example "Starts at 06:15 with 52 °C water so Living room is 20.5 °C at 09:00. With 37 °C water it would have needed to start at about 02:00 and the boiler would have started about 70 times." While it only checks, the sentence starts with "If the E32 planned the heating:";
• the next blocks (start, end, water temperature), when the room should be warm, how sure it is, and how the last morning went ("Last time the plan would have started at 06:15; the E32 started at 06:05. Living room was warm at 08:51.");
• the morning check: "This morning: 6 minutes early.", "Yesterday morning: 12 minutes late.", "on time" or "not warm within 3 hours" (the minutes from the program time until the room was within 0.1 °C of its target). The attribute morning_minutes holds the last seven mornings of that room, oldest first. Firmware before 1.3 shows neither.

While the E32 plans, the sensor Water temperature set by can read The heating plan.

How a planned warm-up ends (firmware 1.3). A planned warm-up starts the burner once. It heats until the program time, or until the room is within 0.3 °C of the coming temperature, whichever comes first. The burn that is on then is finished, not cut: it goes on until the room is at its target, or until the normal room control asks for heat itself (the burner stays on), at most an hour after the program time. On a slow floor the plan may stop earlier and let the floor carry the room to the program time, but only while the room is as warm as the plan expected; a room that lags behind heats on. The plan never starts a second warm-up for the same program step. If the plan has to let go during a warm-up (a comfort warning, a check that fails), Smart warm-up takes over that morning. The plan's warm-up times use each room's own heat uptake, learned from its mornings (the house figure until a room has one).

Your one confirmation. Once its predictions for the main room have been good for a week, the Learning tab shows the button Let the E32 plan the heating under Today's plan (and the E32 device gets it too). It is an invitation, not a fault, so there is no Repairs item. Press it and confirm. The E32 never starts planning by itself. If its plan gets worse (more than one comfort warning a day for three days, or a morning more than an hour early or late), it goes back to heating as before by itself and checks again; once it is ready again, Home Assistant asks you again. The button exists only while the E32 waits for you. With notifications on, The house → Maintenance → E32 ready to plan the heating sends one message each time it is ready.

Comfort style. What the plan weighs, in the E32 Home page's words: Comfort first (warm on time above all; it may use a little more gas), Balanced (warm on time with as few burner starts and as little gas as fit; the standard choice) or Save most (as little gas and as few burner starts as possible; a room may be a little cooler for a moment). The selection Comfort style on the E32 device, Settings → Heating and boiler → Smart warm-up and weather compensation, or the E32 Home page.

Weather forecast. Under Settings → Energy and outdoor temperature → Weather forecast you choose a weather entity with an hourly forecast. Every hour Home Assistant sends the outdoor temperature of the next 24 hours to the E32. A weather entity you chose as the outdoor temperature is used unless you empty the field. Without a forecast, or when the weather service fails, the E32 uses its own daily pattern of the outdoor temperature. Older E32 firmware gets no forecast.

Comfort and boiler care: the self-tuning #

The E32 also sets its own comfort and boiler settings, such as the burner rest between starts and the burner run time, and keeps adjusting them as it learns your house. It changes them by at most one small step a day. After a restart it first waits 2 hours, and 24 hours after its first start or a change that affects the control. You see them, and can change one, under Settings → Heating and boiler → Comfort and boiler care in Home Assistant, or on the E32's Home page under Comfort and boiler care. Back to automatic for all lets the E32 set them all again; Back to start values puts back the values it started with.

Energy, gas and warnings #

Energy inputs and heating advice #

Under Settings → Energy and outdoor temperature you can choose a gas meter (m³ or kWh), a gas price sensor or a fixed price, the calorific value of your gas, an outdoor temperature sensor or weather entity, your boiler's heating power and a water meter (a flow in L/min, or a meter reading in m³ or L). All fields are optional; leave a field empty to not use it. With a gas meter the E32 calibrates its heat and gas estimates. The water meter stays in Home Assistant: it tells tapping from keeping warm (see below), except with a hot water tank, where the E32 counts the taps itself.

The Heating advice sensor and its dashboard section list what could be tuned: short cycling, a maximum heating temperature far above what the house needs, a return too warm for condensing, the water temperature your rooms really need, night setback, hot-water temperature and water pressure. Each item says what was seen, why it matters, what to change and where, with its confidence. It is advice only and never changes a setting; a rule without enough data says what is missing. Since 1.4.2 advice is no Repairs item: a room that stays too cold while it asks for heat and a burner that keeps switching on and off after the self-tuning had its chance are lines under Worth checking on the Learning tab. Repairs is only for faults.

Gas for heating, hot water and keeping warm #

With a gas meter in the energy options, Gas for heating and Gas for hot water share the meter by what the boiler did (without a meter they are an estimate from the burner power the boiler reports). Hot water is split once more: Gas for tapping hot water is what taps used, Gas for keeping hot water warm is the boiler reheating its store or exchanger without a tap, nothing more. Their attributes show per day the rounds, burner minutes and gas. The E32 decides per hot-water episode with the most direct signal the boiler reports (the attribute dhw_method):

• flow: a DHW flow meter. Flow during the round is a tap.
• storage: a boiler with a cylinder (a hot water tank). Since E32 1.4.2 the E32 counts the taps from the boiler's hot water flow, with about how many litres, and a charge only when the tank is really charged. There is no tapping/keeping-warm split: the gas is hot water only. After the E32 has reported a tank for a full day, Home Assistant removes the sensors Keeping warm today, Tapping gas and Keeping-warm gas and adds Charges today (see below). With E32 1.4.1 the taps of a tank stay 0, and the sensor says it needs the E32 update.
• dhw_temperature_fall: neither, so the DHW temperature. A tap brings cold mains water, so the temperature falls deep or stays down. A small tap (washing hands) may only cool the sensor before the round, so a round also counts as a tap when the sensor fell before it faster than it does before this boiler's own rounds at night (01:00-05:00, when nobody taps). The sensor sits where heat enters the store and falls fast after each reheat while the heat mixes through, so this is only a comparison with the nights, not a heat loss. The attribute dhw_baseline says night once the E32 has seen four night rounds since its last restart, and default before that (then only a fall faster than 2 °C a minute counts).
• water_meter: with a water meter in the energy options, Home Assistant decides instead, for every boiler. A round with water flowing during it, or in the 2 minutes before it, is tapping; one without is keeping warm. A round the meter did not cover (no reading) stays in Gas for hot water only. A water meter also sees cold water (a toilet flush), so a round at the same time as one counts as tapping. The meter finds small taps that the temperatures alone miss.

Add heating and hot water to the Energy dashboard; tapping and keeping warm are parts of hot water, so leave them out there.

With a hot water tank (E32 1.4.2). Hot water taps today is the number of taps counted from the hot water flow, with the attributes litres (about), minutes and peak_flow_l_min. Charges today (diagnostic) is the number of real charges, with minutes. The Burner power may read above 100 % during hot water (up to 250 %): some boilers report it as a share of the heating maximum; the boiler-now card says so. Every hot water figure is booked when a tap or a charge ends and reaches Home Assistant within five minutes after that (the E32's own Boiler page within seconds). The weekly summary says "Tank charges". After an E32 restart today's hot water figures are held, not doubled.

Hot water flow (1.4.5). Hot water flow ("Warmwaterdebiet", L/min) is the flow the boiler measures at the tap. It is on the boiler device with the other boiler values, shown and not under Diagnostic, and appears once the boiler's flow has moved (two different values while Home Assistant runs). An adapter such as the Bosch EasyControl fills it with zero or a constant, so a flow that never moves never makes this sensor. Once it exists it stays, and after a restart it comes back with the first report, 0 L/min included. On the Boiler tab the Hot water section shows it right after the temperature and its target: "Tapping now" with the flow while a tap runs, "No tapping" at 0. In 1.4.3 this sensor was hidden and under Diagnostic; 1.4.5 shows it once, unless you hid it yourself. An EMS+ boiler has Hot water flow (EMS+) instead, with the same tile.

Boiler activity says what the boiler does now: idle, heating, tapping, keeping warm, charging the tank, or hot water it cannot sort. A tap shows as keeping warm until its fall is clear, usually within half a minute. On the dashboard's Boiler tab, the Hot water section shows this as a 24-hour timeline next to the boiler's heating state; the day strip of the house card on the Overview shows it for today. The chart Gas per day under Today and this week always shows heating and Hot water (total). A second small chart, Hot water: tapping and keeping warm, appears only when both gas sensors exist and the hot water is not a tank. While the boiler heats a tank the card legends say Charging the tank. On the E32's own Overview, the boiler history has a hot-water strip: the share of each 5 minutes tapping and keeping warm (a cylinder's charging counts as keeping warm there).

Daily summary and warnings #

The Heating problem sensor answers "is my heating OK?". It turns on only for real problems that last:

• a room without a usable measurement for 30 minutes;
• no report from the E32 for 10 minutes;
• low or high water pressure;
• a room that asks for heat but stays more than 0.5 °C below its target for 3 hours (a gap in the E32's data starts the wait again);
• the E32 online but without a working link to Home Assistant for 15 minutes;
• after the switch-over: a warning of the E32's active control for 5 minutes, or the E32 waiting 10 minutes for you to confirm the switch-over again. A new installation that never let the E32 control its boiler is not a problem while it waits: its next step is the boiler test on the Boiler page.

The burner switching on and off often is on this list only when it persists (E32 1.1.0): the E32 first lengthens the burner rest step by step, and shows it as learning information. Only when it reaches the limit of the rest, or three days pass without fewer starts, it says "The burner keeps switching on and off too often, even after a longer rest. Have the boiler's settings checked." and Home Assistant lists "Burner switches on and off too often". With an older E32 it stays learning information.

If the E32 stays online but sends no room and boiler values for 15 minutes, Home Assistant shows them as unavailable and the list gets a reason that says the E32 is online but its room and boiler values have not come in; restart the E32. Old learned values then no longer show as current.

Each problem except the water pressure (which has its own message) also appears under Settings → System → Repairs as Heating needs attention, and clears itself once the cause is gone. On the dashboard, the band of the house card turns red while the sensor is on and names the first reason; a tap on it opens Repairs. The sensor's problems and reasons attributes say what is wrong, so you can use it in your own notification automation.

The Daily summary sensor on the OpenThermostat device shows the last finished day; its attributes hold the last two weeks (three weeks are kept). Per day: burner time, burner starts and short runs (under 10 minutes), gas for heating and hot water (and tapping and keeping warm), the outdoor temperature when one is set, per room how long it asked for heat and how long it took to reach a raised target (late after 2 hours), and the missed comfort minutes: the minutes, added up over the rooms, that a room was more than 0.3 °C below its target while in use (not paused for away, a holiday or an open window), as the E32 counts them; a late morning counts too. With older E32 firmware it is per room, the minutes a room asked for heat more than 0.5 °C below its target after its first 2 hours. The attribute counts of Missed comfort time (total) says which. Only time with E32 data counts; a day with less than 20 hours of data is marked partial. Burner time (total), Burner starts (total) and Missed comfort time (total) are running totals with long-term statistics, so their change per day is the daily figure. The Learning tab of the dashboard shows yesterday in figures, with the missed comfort of the last days as bars. The gas and the burner hours of the last days are bars under Today and this week on the Boiler tab.

Where the entities are #

On a device page the entities you use every day stand in the main list: the thermostat, Temperature, Heat demand, Reason, gas, Boiler activity, Heating problem and the hot water taps. Settings (for example a room's Heating: On, Heat along only or Off, and Off until) stand under Configuration, and figures that only inform (Target temperature, Control status, Learning status, Recommended water temperature, Smart warm-up start (was Predicted heating start), Burner starts last hour, Requested water temperature, Known about your house, Boiler response, the three running totals and the yesterday figures) stand under Diagnostic; entities that already exist move there too. Entity IDs stay the same on updating; some names changed. The running totals say what they are: Burner starts (total), Burner time (total) and Missed comfort time (total) (they were "... today"). The yesterday figures say "(yesterday)" in their name, for example Heating energy per degree-day (yesterday) in kWh/°C·d. Device uptime keeps no long-term statistics any more. The first time the integration starts after the update it relabels the old degree-day statistics to the new unit and deletes the old uptime statistics; the history of the other figures stays, and no repair is shown.

Since 1.2.0 the E32's own figures change in steps, so Home Assistant keeps a history row only when something really changed: Device uptime in steps of 0.1 h (every 6 minutes; a restart still shows as a drop), Free memory, Minimum free memory and Maximum allocable memory in whole kB. Device uptime also carries the E32's own MQTT figures of the last minute (messages, bytes, queue peak, latency) and, in its history, the disconnects and dropped messages since the E32 started. The diagnostic sensor Last restart (E32 1.2.0 and newer) says when the E32 started and why: power (on, or a power dip), an install or a restart request, an automatic restart by the E32 (with the reason), or a crash; with the previous run's uptime and lowest free memory. Older firmware never shows it.

Since 1.4 the diagnostic sensor Errors on the same device (OpenThermostat E32 Errors) counts the error lines in the E32's system log since it last started (it starts at 0 again after a restart; clearing the log on the E32 does not reset it). Its attributes show the last error line (at most 120 characters; a line that might hold a password or another private value is hidden, as in the log) and when it was logged. The figure arrives with the E32's heartbeat, once a minute. A few errors after a restart or a network drop are normal; a count that keeps rising tells you to look at System → Diagnostics and system log on the E32. It never raises a repair. E32 firmware before 1.4 never shows it.

Devices since 1.2.0. An installation has three kinds of devices: OpenThermostat E32 (model E32 V2: the rooms' controller, the house, what it learned, gas, its own diagnostics, backup and firmware), the boiler, named after the model you chose ("Nefit EcomLine HRC 22"; Boiler without a choice), with all its values (water to heating, pressure, burner power, display code) and its settings, Boiler recognition and Changing boiler settings, and Thermostat on the boiler bus for another thermostat the E32 hears on the bus. The bus address and product number are the boiler's model and model ID, no longer part of its name. Entity IDs and history stay; only the device changes. The seven "Old: ..." energy counters are gone (their history stays in the recorder): the figures are Gas for heating and Gas for hot water, and on boilers that send them the Estimated energy ... counters. After the takeover Ready for E32 control goes (it comes back in a trial run), the everyday Requested water temperature stays, and Water temperature sent to the boiler (the last request actually sent) is diagnostic. A boiler value whose setting has its own control ("... (boiler setting)") is disabled while that control exists.

Radiator valves #

Radiator valves (TRVs) follow their room in one of two ways:

• Zigbee2MQTT valves on the same MQTT broker: the E32 drives them itself. Home Assistant is not needed for it; it only shows and configures the valves.
• Any other valve Home Assistant controls (ZHA, Z-Wave, Shelly, a cloud integration, and so on): it is a climate entity in Home Assistant, and Home Assistant drives it on the E32's behalf, with the same rules.

Supported models:

The Zigbee2MQTT keys come from the Zigbee2MQTT device pages; check them on your own valve before you rely on them. Which devices were checked against what a real device sends, and how, is in the device matrix. A valve or thermostat that is not read well: Add a device: send a capture.

Any climate valve through Home Assistant (1.4.4). Every valve Home Assistant knows as a climate entity works, whatever the brand, also one that only has a temperature range: its target is read from target_temp_low, and set with target_temp_low while its target_temp_high is kept. A setting device that only reports a range (a Bosch Room thermostat II) works the same way.

For the Sonoff valves the E32 first sends the room temperature and only then selects it as the valve's sensor, because Zigbee2MQTT refuses that choice without a value. It reads which sensor the valve reports: older Zigbee2MQTT versions call the choice external, newer ones remote_temperature, and the E32 uses whichever your valve reports. If the valve still uses its own sensor 10 minutes later, the E32 asks again.

A valve that restarts without telling (E32 1.4.6, issue #19). After a battery change or its own update some Sonoff TRV-ZBT valves silently go back to their own sensor and regulate on the radiator's temperature. The E32 compares what the valve reports as its temperature with the room temperature it sent. If it differs by more than 1 °C in every report for 30 minutes, the E32 sends the room temperature and the sensor choice again; that is 30 to 45 minutes after the restart. It tries at most three times. If the valve still does not follow, it is left alone and its tile says not responding to the E32 until it follows the room again. It is checked only for a valve the E32 drives, with a room temperature, outside summer mode and while the valve is not switched off, and only for this model: other models are not checked, and a valve whose own sensor happens to read within 1 °C of the room is not noticed. Home Assistant shows nothing while the E32 waits and tries. The heat mode keeps the valve off its own week schedule; the E32's program is the only one. The valves' own settings, such as the opening limits, window detection and child lock, stay yours to set in Zigbee2MQTT.

Choosing the valves. In Home Assistant: the dashboard's Settings → Rooms → the room → Radiator valves (without the dashboard: Configure → Rooms → Edit or remove a room → Edit room, section Radiator valves of the room form, also when you add a room). Just pick the valves' climate entities, of any brand; OpenThermostat's own thermostats, the room's thermostat source and the valves of other rooms are not offered. OpenThermostat works out the route of each valve itself and shows it in plain words:

• works without Home Assistant: a Zigbee2MQTT valve of a model the E32 knows (Bosch BTH-RA, Sonoff TRVZB, Sonoff TRV Gen2, Tuya TV02) on the E32's Zigbee2MQTT base topic. Its Zigbee2MQTT friendly name comes from the device's MQTT topics, so a device renamed in Home Assistant still works.
• through Home Assistant: every other valve, including a Zigbee2MQTT valve whose model is not recognised.

Under Choose the models myself (advanced) you can still choose the model of a Zigbee2MQTT valve (or Through Home Assistant) after saving. A valve that was set up before keeps its model. A valve set up through Home Assistant that the E32 can drive itself moves to the E32 the next time you save the room (the form shows it first); only choosing Through Home Assistant for it under Advanced keeps it there, and that choice is remembered. A stored Zigbee2MQTT valve Home Assistant does not know is listed under Kept valves and keeps working. On the E32 itself: the room card on the Rooms page has a Radiator valves block with its own Save valves button; Home Assistant valves show there read-only, as Home Assistant climate entity (set in Home Assistant). At most 4 valves per room and 16 in all.

Nothing happens until you switch it on. Each room has a Radiator valve control switch (entity ID ending in _valve_control), off by default. The E32 sends to a room's valves only while that switch is on and the E32 controls the boiler itself (active control after the attended switch-over). During the trial run, or with the switch off, nothing is sent to any valve, and a room without valves behaves exactly as before. The session field actuator_output_enabled says whether the E32 drives valves right now.

What the E32 does with them. It sends the room's target as the valve's setpoint and, where the valve takes one, the room's own measured temperature; the valve's own regulator then sets its opening. Valves that report their position feed back into the water temperature: when every valve that asks for heat is only partly open the water temperature goes down a step, when one is fully open while its room is still more than 0.5 °C too cold it goes up a step; at most 1 °C per 10 minutes and 8 °C in all. The water temperature limits and the boiler's own maximum still apply.

All valves closed. When every room that asks for heat has only valves that report themselves closed (5 % or less) for 10 minutes, the E32 stops its boiler request (reason valves_closed): there is no open circuit to heat. A room without valve control (for example the floor heating) keeps the request going, and a valve that stopped reporting never counts as closed.

Valves driven by temperature. A valve that cannot report its opening (the Sonoff TRVZB and TRV Gen2, the Tuya TV02, Other) is driven by temperature: the E32 decides the temperature, the valve only opens and closes. It is left out of the average opening. On the room card the valve's tile says "set to 20.5 °C": what the valve reports as its setting, else the temperature the E32 gave the room's valves ("set to 8 °C" while the room is off). The sensor's attributes hold the same: set_to_c, set_to_text, driven_text and driven_by_temperature (the valves' names; until 1.3 self_regulating).

Battery saving. A new setpoint only on a change of at least 0.5 °C (at most once a minute, refreshed every 6 hours); the room temperature at most every 10 minutes and at least every 25 minutes. A simulated two weeks with four valves costs well under 2 % battery per valve.

Home Assistant valves. Home Assistant sends such a valve the room's target (8 °C while the room is off), rounded to the valve's step and within its own limits, on the same rules: only while the room's valve control is on and the E32 controls the boiler itself, a new setpoint only on a change of at least 0.5 °C, at most once a minute and again after 6 hours. Once per control period it sets the valve to heat when the valve has that mode; it never turns a valve off. It does not send the room temperature, and these valves do not feed back into the water temperature (a room with one never counts as all closed). Health: a valve that is unavailable for 2 hours is offline; the battery comes from a battery sensor on the valve's device in Home Assistant (or its low-battery sensor). The valve counts in the room's Radiator valve position, Radiator valve battery and Radiator valve problem entities and in Repairs, like a Zigbee2MQTT valve; on the E32 page its state reads Driven by Home Assistant. A failing service call is logged once and tried again a minute later at the earliest.

A valve turned by hand (1.4.2). The E32 watches the set temperature and the mode of every valve it drives, in every house mode. When someone turns a valve it puts the room's temperature back within a minute (for a gateway valve at its next status poll), at most once a minute. If the valve does not take the value it tries again after 10 minutes, three times, then gives up until the valve shows the E32's value again. A valve that returned to its own program (Sonoff, Tuya, Bosch) is set to manual again at most once an hour, three times. A valve someone switched off on the valve itself is left off. A radiator valve that is the room's setting device is not driven by the E32 at all (one role per valve).

A room with many valves (1.4.5). The E32 sends a room's valve details to Home Assistant as one message of at most 1,536 bytes. A room with up to eight valves with long names can come to more; since E32 1.4.5 the E32 then leaves the least important details out, the valves heard least recently first: the moment of a finding, the old readings of a valve that is offline, the model, the finding, and last the readings of the others. Name, state, link and role of every valve stay. Diagnostics notes shortened beside the room (the Valve position sensor has the attribute trimmed). A shortened valve can show a blank battery, no "set to" line or a finding without its time; before 1.4.5 such a room dropped out of Home Assistant altogether. Nothing needs to be done.

Message too large to read (1.4.4). The E32 reads the state a Zigbee2MQTT valve sends up to 6 KB. A Sonoff TRV-ZBT sends about 2.3 KB (seven week programs and an update note), a Bosch thermostat about 0.7 KB; both are read, so battery, set temperature and mode show (before 1.4.4 anything above 1 KB was dropped and the valve stayed unknown, issue #15). A message that is larger than 6 KB, cut off or broken cannot be read: the valve then says Message too large to read with the size of the last message (for example "2.3 KB") on the E32 Rooms page, and the room counts it as a valve that is not working. It goes by itself with the next state the E32 can read. Since E32 1.4.5 a valve that was read a moment ago says so on the third unreadable message in a row, which takes minutes (a valve reports every few minutes; one or two unreadable messages between readable ones change nothing). With E32 1.4.4 and older it kept its reading for 2 hours first. What to do: report it with the valve model and Zigbee2MQTT version (the size helps); nothing on the valve needs to change.

When something fails.

• A battery below the limit (20 % unless you change it under Settings → Devices → Batteries): a message that names the valve and a red badge on the dashboard, no Repairs item; the valve is still driven.
• A valve that has not reported for 2 hours: a Repair; the room is shown as degraded but keeps heating on its other temperature sources. When the valve is back it gets its mode, setpoint and room temperature again.
• No room measurement (Home Assistant down, a sensor gone): the E32 stops sending the room temperature, so the valve falls back to its own sensor, and after 30 minutes the room stops asking for heat. The E32 never heats blind.
• A room with only one temperature source: if it fails, the room stops asking for heat after 30 minutes. A second source, for example a Bluetooth thermometer, covers that (no Repair since 1.4; the room form says so at its temperature sources).
• The E32, the broker or Zigbee2MQTT gone: the valves keep regulating on their last setpoint.
• Home Assistant gone: Zigbee2MQTT valves stay driven by the E32 (as long as the broker runs); Home Assistant valves keep their last setpoint until Home Assistant is back.

MQTT broker. The E32's broker user must be allowed to subscribe to zigbee2mqtt/<valve name> and to publish to zigbee2mqtt/<valve name>/set (or the base topic you use in Zigbee2MQTT).

Shelly devices: floor pump, probes and valves #

With E32 firmware 1.1 (E32 V2 only) the E32 drives three kinds of Shelly devices itself, over their local HTTP interface on your home network. Home Assistant, the message broker and the Shelly cloud are not in the chain: they can all be away and the pump, the probes and the valves keep working. Home Assistant only shows what the E32 reports.

Limits: at most 6 Shelly devices, at most 5 valves per gateway (more need a second gateway), at most 24 valves in all and 8 per room (more than 4 per room only through the gateway), at most 2 heating circuits. Devices are added by their IP address; there is no network search, so give each one a fixed address in your router. Valves are paired with the gateway in the Shelly app first. Then Look for valves at the gateway lists what the gateway has paired (its number and the gateway's name for it) and one tick adds a valve; or you type its number (200, 201, …). The E32 asks the gateway only when you choose it, one question at a time, never on a schedule.

Budgets in one line: the E32 asks the Plug every 15 s, The Pill and each valve about once a minute (at most 12 questions a minute per channel); each valve gets at most one command per 2 minutes and 200 a day; the pump at most one change a minute; MQTT gets one small document per circuit and one for the probes, on a change and every 5 minutes.

Health words #

The Overview has one line for all of them: "A Shelly device has a problem: see System → Devices". Home Assistant raises a Repair for each problem that matters (see below).

Heating circuits and the pump rule #

A heating circuit is a group of rooms with its own pump or water, such as the floor heating. Set it up on Home → Heating settings → Heating circuits: its rooms, its pump (a Plug) and its probes. The pump rule, in order:

1. Too hot: the water to the floor stays 5 °C above its highest temperature (default 50 °C) for 2 minutes. The pump goes off, also against a switch by hand. It starts again once the water is below that.
2. Frost: a floor room below 7 °C, or a probe below 5 °C: the pump runs.
3. Heat: a room of the circuit asks for heat and the boiler heats (or the water to the floor is warm): the pump runs, whatever the water temperature.
4. Run-on: after the heat, so the rest of the heat reaches the rooms. Once on, at least 5 minutes.
   • Without both water probes: 10 minutes (Pump keeps running after the heat).
   • With both water probes, while the water is warm: as long as the water to the floor is at least 2 °C warmer than the water back, and at least the 10 minutes while it is. A smaller difference ends it after 1 minute (a short dip does not). At most 30 minutes (Run on while the water is warm, at most, 0–120). It also ends once a room of the circuit is 0.5 °C or more above its target, and when a probe has no fresh reading (3 minutes), the 10 minutes finish it. Too hot (rule 1) always wins. The card says "Running on: the water is still 3.8 °C warmer than the water back".
5. Against sticking: after 7 days without running, 1 minute in the daytime.

You can switch the pump by hand (On or Off, 30 minutes to 24 hours), on the E32 page or with Floor pump mode in Home Assistant. After that time it is automatic again.

Observe first. "Pump control by the E32" is off by default. Then the E32 works the rule out and shows it ("The E32 would switch the pump on now: a room needs heat."), but switches nothing. Switch it on after watching it for a few days. Even then the E32 switches the pump only while it controls the boiler itself.

The dead man. At rest the pump is on: set the Plug to "on after a power cut" in the Shelly app. When the E32 switches the pump off, it tells the Plug to switch back on after 30 minutes, and repeats that every 10 minutes. When the E32 or the network fails, the pump is on again within 30 minutes.

Hardware safety stays. A maximum limiter (STB) of the floor stays in series. Only the pump's minimum switch (a thermostat that holds the pump off below 35–40 °C) is bridged or set to its lowest, by an installer. With that switch still in the way, the E32 says "The pump draws no power".

Where the heat goes (zones) #

With a circuit, the E32 works out who asks for heat: the floor only, the radiators, the floor and the radiators, or nobody. The water temperature follows the circuits that ask: a floor alone gets low water (its design water is 40 °C at −10 °C outside), the radiators their own. The Home page and the Home Assistant sensor Heat goes to show it. Two extra lines can appear:

• Held at the lowest water temperature: the floor water is too hot. Only the floor asks, and its water is too hot: the E32 asks the boiler for its lowest water temperature until the mixing valve brings it down.
• No open path for the water: the floor pump is off and the radiator valves are closed. A room asks, but the water cannot flow. With valve control on, the E32 then stops the boiler as when all valves are closed.

The learning uses the floor's real supply (the probe after the mixing valve) and pauses while the floor pump is off, so it learns the floor's true lowest water temperature. The first time the pump runs with power, the floor's lowest learned values are learned again once. With loop probes, the E32 compares the floor loops over hours of floor heat and says when one returns 3 °C or more warmer or cooler than the others (for example "Floor loop 2 returns 4 °C cooler than the others"). It changes nothing itself.

Valves through the BLU Gateway #

A command is "sent", then "confirmed by the valve" once the valve's own report shows it. When the answer does not come, the command is "not sure it arrived": the E32 then waits for the valve's next report and never sends it blindly again.

Keep this radiator open (as the water's path). All radiator valves shut and the floor pump off while the boiler heats is only safe with a bypass in the boiler or the circuit. Until you know yours has one, tick this for one radiator, for example the bathroom. While the boiler heats and no other way is open, the E32 holds that radiator open. Not for a floor loop valve.

When something is away #

Everything picks up again by itself; nothing needs to be confirmed.

In Home Assistant #

• Each circuit is its own device (Floor circuit) with Floor pump (running or not), its reason in words, its power, Floor supply, Floor return, their difference, Floor circuit problem, and the select Floor pump mode (Automatic, On for 1 hour, Off for 1 hour). Probes that no circuit uses appear on the E32 device (Floor loop 2 return, …).
• Heat goes to (diagnostic, on the E32 device): where the heat goes now, with path and limited as attributes.
• Settings → Heating and boiler → Heating circuits on the dashboard (without it: Configure → Heating and boiler → Heating circuits): Pump control by the E32, Highest water temperature to the floor (30–70 °C, 50 by default) and Run on at most (minutes) (0–120, 30 by default), the same settings as on the E32 page. Floor pump reason says "Running on (rest heat)"; while the water is still warm its attributes add warm and the difference delta_c.
• Settings → Rooms → the room → Radiator valves: BLU Gateway valves, Floor loop valves and Keep this radiator open.
• Settings → Devices on the dashboard, or Configure → E32 devices → Shelly devices without it (1.3): the devices the E32 knows, each with its state and a gateway's valves; Add a device (on the dashboard: Shelly device, a screen called Add a Shelly device; its address, then the E32 tests the connection as on its page, then what it does, a name and the device password, which goes to the E32 only), Add a valve to a BLU Gateway (by its number), Remove valves and Remove a device. Each is one save of the whole Shelly list, read and written in one sign-in, so a change on the E32 page meanwhile is kept. A Plug that switches a circuit's pump is removed only after the pump left the circuit. Since 1.4.1 the dashboard's Settings → Devices also gives The Pill's probes their pipes (Save probe roles) and looks for valves at the gateway; a device's name, address or password stay on the E32 page.
• Repairs: the pump's Plug does not answer, refuses the password, has another device at its address or reports an error; the pump takes no power; water too hot (an error); a probe gives no reading; the BLU Gateway does not answer; a valve not found at the gateway. Each clears itself once the cause is gone.
• A circuit, probe or valve that leaves the E32 takes its entities along.

The trial run and the switch-over #

Reading the trial run comparison #

If a thermostat controls your boiler over the EMS bus, the comparison puts the E32's decision next to what that thermostat actually asked of the boiler. You find it on the E32 Boiler page under "Comparison with your thermostat (today)", below the boiler test. Home Assistant adds today's figures as sensors (heating time and burner starts today for the E32 and the thermostat, and their agreement) once it has seen such a thermostat; a home without one gets no comparison sensors. The generated dashboard links to the comparison from the Learning tab ("E32 compared with your thermostat") only during the trial run, and only while that thermostat is heard. Once the E32 controls the boiler and hears no thermostat any more, the link and the Comparison page disappear, and after about ten minutes Home Assistant removes the comparison sensors (their history is kept; a sensor you renamed or changed stays). They come back by themselves if you return to a trial run with a thermostat on the bus.

The table below shows the last seven days.

Ready for the E32 to control the boiler? #

Right above the comparison, the Boiler page shows the check Ready for the E32 to control the boiler?. The E32 judges its own trial run, so you need no Home Assistant, token or script for it. Each line is green (passed), orange (waiting for more data, with the progress so far, such as "51 of 72 h") or red (with what to do):

Only when every line passes does it say "Ready: start the boiler test and takeover above"; that test is the last step (see The attended switch-over). The trial run is optional. The figures cover the last seven days and are kept over restarts. In active mode the check is hidden.

Without an EMS thermostat on the bus there is nothing to compare. The check says so and lists only the stability, the room sources, the boiler heard on the bus (in the last 5 minutes) and the boiler maximum known (the E32 read the boiler's heating limit itself).

Home Assistant shows the same check (until the E32 controls the boiler) as the sensor Ready for E32 control on the E32 device (Ready, Waiting for more data, Not ready, or Not applicable once the E32 controls the boiler), with each line's result and figures as attributes, and on the Learning tab of the generated dashboard (next to the comparison during a trial run). It adds one thing the E32 cannot see of itself: when Home Assistant did not hear the E32 for five minutes or more, the 72 hours count from the moment it was heard again. The sensor raises no repair issue.

The trial run does not show how the boiler and its adapter react to the E32's request; that is tested during the switch-over.

The attended switch-over #

The firmware can control the boiler, but it never starts on its own: it sends nothing to the boiler until you confirm the takeover. Switch over only with someone present at the boiler.

Which route the E32 offers. A new E32 without a stored room plan listens to the boiler bus for two minutes. When another thermostat still asks the boiler for heat, it starts with the trial run ("Your boiler still gets requests from another thermostat, so the E32 first runs alongside it"); when none is heard, it starts in active control with the boiler test ("No other thermostat was found on the boiler bus, so you can go straight to the boiler test"). Until it knows, it says "Checking the boiler bus…" and stays in the trial run. Choose the other route at any time with Trial run first (compare with your thermostat) or Go straight to the boiler test. A stored plan keeps its mode.

Boiler test and takeover (optional). Boiler → Boiler test and takeover (the Rooms page links to it from Active control): no other thermostat on the boiler (an old one disconnected), confirm the takeover, start heating, hot water while heating, stop heating, done. It is the only boiler test (the attended heating test of the Boiler page is retired), and no existing thermostat is required: the page speaks of an old thermostat only when the E32 has heard one. The E32 checks every step from the boiler's reports and shows each as passed, waiting or failed in plain words; the details and pass criteria are in INSTALL.md section 12. Its temporary room target has an end time and never changes the week program. When a safety rule stops it, the page says "Stop and give control back to your thermostat" (without a thermostat the E32 ever heard: "Stop E32 control") with the steps. The E32 remembers the result over restarts and updates ("Last test: passed on 1 Nov 2026, 21:12."). I have already done this test keeps your own mark with its date, shown as a mark and never as a passed test; Undo my mark takes it back. An E32 that has controlled this boiler before shows the test as not needed, folded away, with Run the test anyway. The Boiler page shows the same in one line with a link ("Boiler test: passed on … · Open"), and Home Assistant on the sensor Ready for E32 control (boiler_test_summary and the other boiler_test attributes).

By hand, following the switch-over procedure, it involves:

1. Physically disconnecting the existing thermostat from the boiler bus. Two thermostats must never send boiler requests at the same time.
2. Confirming on the Rooms page: "My thermostat is disconnected from the boiler — let the E32 take over". The E32 then waits for fresh room readings and the boiler bus before it takes over.
3. Tests with someone at the boiler: start, stop and burner power; hot water while heating; an E32 restart; loss of Wi-Fi, Home Assistant and room measurements; and the boiler adapter's behaviour when the E32 stops sending.
4. Handing back with Give control back to my thermostat (without a thermostat the E32 ever heard: Stop E32 control): the E32 asks the boiler for zero for one minute, then you reconnect the thermostat if there is one.

Safeguards in active control: the E32 stops and warns when another thermostat still sends boiler requests; without room measurements it asks for no heat until a reading returns; frost protection switches on below 8 °C; the requested water temperature never exceeds the plan maximum (at most 80 °C) or the boiler's own maximum heating temperature setting. While the E32 controls the boiler, the installer check (System → Diagnostics and system log → For the installer: readings, zero-only check) is refused; the boiler test does not start while that check or a boiler settings change uses the connection to the boiler.

After the switch-over follow one to two weeks of active control with daily checks; the Daily summary in Home Assistant gives the figures for each day.

Boiler settings (preview) #

Your boiler keeps its own settings in its memory, such as the hot water temperature. The E32 reads them itself (see Your boiler on the bus). With E32 firmware that has boiler settings, it can also change a few of them, but only after you allow it. This is off by default: while it is off, the E32 only reads these settings. Without that firmware, Home Assistant shows no Boiler settings item and the E32 Boiler page shows no Boiler settings block.

Where. In Home Assistant: the dashboard's Settings → Heating and boiler → Boiler settings (preview) (without the dashboard: Configure → Heating and boiler → Boiler settings). While changing is off, the screen shows the everyday settings with their values under the card that allows it (read only). The line on top says whether changing is on ("Changing boiler settings: on: 2 of 12 changes used today"); the list shows each everyday setting with its value, whether it is verified on your boiler and Changed by the E32 when its value came through the E32. Tap a setting to change it. On the E32: the Boiler page, block Boiler settings. All of them change the same settings.

Switching it on and off. Home Assistant: under Allow the E32 to change boiler settings read the text, tick I understand: I watch the boiler after a change and choose Allow. The E32 page: the switch Allow the E32 to change boiler settings shows the risk text, then I understand and Switch on. To switch it off: Stop the E32 changing boiler settings at the bottom of the screen in Home Assistant (it asks first), or the same switch on the E32 page. A change you are watching is put back first; settings you kept earlier stay as they are on the boiler.

The settings. Everyday settings: Heating on the boiler, Maximum heating temperature (boiler) (on the E32 page: Maximum water temperature (boiler)), Hot water on the boiler, Hot water temperature (usually 50 to 60 °C) and Hot water comfort. The installer settings (burner power, switching margins, burner rest, pump run-on, pump speed and mode, and the hot water details such as circulation and disinfection) are under Advanced (installer settings) in Home Assistant: it asks first (I change this at my own risk) and then stays open for 30 minutes ("Advanced open, 25 min left"; Close closes it sooner, and so does stopping), and under Show installer settings (at your own risk) on the E32 page. There the everyday settings also offer the boiler's whole range. A setting your boiler does not support is hidden.

How a change works.

• A setting verified on this boiler is written at once and read back: "Written and read back".
• Any other setting is not yet verified: try it while you watch. No setting is verified on any boiler yet, so for now every change is watched. After the change, Watch your boiler for up to 15 minutes. Then choose Keep the new value or Put it back (on the E32 page: Keep or Put back, with a countdown). If you do neither, or choose Done (the E32 puts it back after 15 minutes), the E32 puts the old value back by itself, and Home Assistant shows the notification Boiler setting put back. While it runs, the card The change you are watching now opens the dialog again.
• Switching the heating or the hot water off asks first (Really switch it off?): while you watch it stays off for up to 15 minutes; if you keep it, it stays off until you switch it on again.
• During a watch Home Assistant keeps no connection to the E32 open, so every other change keeps working. On the E32 page, only the browser that started a change can keep it or put it back.

Limits. The E32 changes one setting at a time, at most 12 a day, and the same setting at most every 30 seconds. It refuses a value outside the setting's range, and a maximum heating temperature above the highest water temperature of your home (raise that limit on the Home page first). A setting can be changed while the E32 heats with the boiler; it changes nothing while the boiler test, a reading or a firmware update uses the connection to the boiler, or just before it restarts or updates ("The E32 is about to restart or update; try again in a minute"). Boiler settings work on EMS Classic boilers only, for now: on an EMS+ boiler the E32 only reads them.

When putting back fails. Home Assistant shows the repair Check the boiler: a setting could not be put back, and the E32 page a red box Could not put it back: check the boiler with Acknowledge. Until you confirm, the E32 changes no boiler setting. Check the setting on the boiler itself and set it back there if needed; then choose Boiler checked on the screen (or Fix in the repair) in Home Assistant, or Acknowledge on the E32.

In Home Assistant. The diagnostic sensor Changing boiler settings on the boiler device says Off, Allowed, Waiting for you: keep or put back, or Check the boiler, with the last setting, its result and when. An everyday setting that is verified on your boiler also gets its own control on the boiler device, named "... (boiler setting)" (its read-only value is then disabled); installer settings never get one.

The protocol details and what could not be verified yet are in EMS boiler settings.

EMS+ boilers and boiler recognition #

EMS+ (also called EMS 2.0) is the newer boiler bus of Bosch, Buderus, Nefit, Junkers and Worcester boilers. With E32 firmware that has the My boiler block, the E32 reads an EMS+ boiler and shows what it would ask of it. It controls an EMS+ boiler only when that boiler model is Verified in the E32's list of boiler models. Today no EMS+ model is verified, so the E32 controls no EMS+ boiler yet. Your EMS+ thermostat stays in charge.

Getting a model verified needs testers with that boiler: see the tester program.

Boiler recognition (My boiler) #

The E32 asks the boiler which model it is (its product number and software version) and listens to which kind of messages it sends (EMS Classic or EMS+). It compares that with its own list of boiler models. The answer is on the Boiler page, in the block My boiler, under the boiler test: the model, the product number, the version, the protocol and one sentence. A boiler outside the list is named from EMS-ESP's device library, for example "Nefit TopLine / Buderus Logamax plus GB162"; a product that library does not know reads "Unknown model (product 99, version 1.2)".

Under the sentence, Why gives the reason:

The state keeps one of five names (Home Assistant's sensor Boiler recognition uses the same five); the sentence follows the protocol, so it is true for both. The block then says what it means ("The E32 reads your boiler and can control it." for an EMS Classic boiler and a verified model, otherwise "The E32 reads your boiler and shows what it would ask; it does not control it yet.") and what to do next. After A different boiler it shows the button I changed the boiler. Did you replace the boiler? Choose it: the E32 then recognises the new boiler from scratch, in about 10 minutes, and controls it only if its model allows it. Did you not replace it? Check the cable between the E32 and the boiler. Boiler settings and all boiler data jumps to the rest of the page.

On an EMS Classic boiler the state is information only. Whether the E32 controls a Classic boiler still depends on the boiler test and your takeover, as before (see the attended switch-over). So a Classic boiler that is not in the list says Not in the list yet: the E32 controls it the Classic way, and the takeover still works. Only for an EMS+ boiler does the state decide.

The E32 recognises the boiler again after every start. A tested state of an EMS+ boiler is kept only until the E32 restarts; after a restart it is Reading only again, until the list itself says more.

What the E32 reads from an EMS+ boiler #

An EMS+ boiler sends most values by itself. The E32 reads 32 values from it:

• Status: the display code (three characters, as on the boiler's own display), the cause number, and the status display information.
• Water and burner: the water temperature to heating, the water back, the boiler's own water temperature target, the flue gas temperature, the burner power asked and the burner power, burner on, the flame current, heating active, the burner rest left before its next start, and the water pressure.
• Pump: heating pump on, and its speed.
• Hot water: hot water active, the 3-way valve, the hot water temperature and its target, the flow at the tap, hot water on or off, and the hot water temperature set on the boiler.
• Counters: burner starts and burner time, heating starts and heating time, hot water starts and hot water time.
• The boiler's own settings: heating on or off, the maximum heating temperature and the maximum burner power. The E32 asks for these (and for the hot water settings) shortly after a start and every 6 hours. It waits while the boiler makes hot water. Asking is a question, not an order: it changes nothing on the boiler.
• Faults: the last fault the boiler logged and the fault active now. An active fault of the "locking" kind counts as a lockout for 3 minutes.

The values appear on the Boiler page and, in Home Assistant, as entities of the boiler. Home Assistant only creates an entity for a value that came in. The E32 also reads the identity of the boiler (product number and version).

The E32 never sends anything to an EMS+ boiler other than these questions, until the boiler's model is verified, or during the attended test below.

The trial run on an EMS+ boiler #

On an EMS+ boiler the E32 runs the usual trial run: it follows your rooms and week programs, and works out what it would ask of the boiler. It compares that with what your EMS+ thermostat asks. The Boiler page shows the comparison under Comparison with your thermostat (today), and Home Assistant in the Comparison view (see reading the trial run comparison).

The E32 also keeps four figures side by side: the water temperature it would ask, what the thermostat asks, the target the boiler holds now, and the boiler's maximum. These are in the E32's status data and in a shared result; the pages do not show them yet.

The boiler test on the Boiler page does not run on an EMS+ boiler. The E32 does not offer the switch-over for it until the model is verified.

When the E32 may control an EMS+ boiler #

All of this must be true, every time:

1. The E32 recognised the boiler since its last start (10 minutes).
2. The boiler's model is in the list, and verified both for asking for heat and for stopping.
3. No other thermostat asked the boiler for heat in the last 10 minutes.
4. Nothing went wrong since the start (see below).
5. You confirmed the takeover, as for any boiler.

Tested by you is not enough today. Whether a passed test on your own boiler may let the E32 control it, before a review, is still an open question for the project owner. Frost protection follows the same rule: on an EMS+ boiler that is not verified, the E32 does not heat for frost protection either. Your thermostat does.

While the E32 controls a verified EMS+ boiler (no boiler today):

• It sends its request at every turn the boiler gives it, and repeats it every 30 seconds while the request still changes.
• The boiler must show the new target within 30 seconds. A target of 0 means the boiler is locked out: a warning, not an error.
• While the boiler makes hot water, the E32 waits, unless the model is verified for hot water during heating.
• Twice in a row a target that does not match, or another thermostat that asks for heat: the E32 sends its stop, goes back to the trial run and stays there until the next start.

The attended test #

This test proves, on your own boiler, that the E32's request for heat works and that its stop really stops the boiler. It is only for testers who want to help, and only with someone at the boiler. The steps are in the user guide and the installation guide.

Who can start it. The E32 starts the test only when:

• the boiler is an EMS+ boiler, recognised since this start, and not "a different boiler";
• its model is in the list and not verified yet, and its stop is not known to fail;
• you said that the thermostat is disconnected, and the E32 heard no other thermostat for 10 minutes;
• the E32 does not control the boiler itself, and nothing went wrong since the start;
• no firmware update, boiler test or boiler setting change is busy.

Where. On the E32 Boiler page, in the block Test your EMS+ boiler under My boiler. The block shows only on an EMS+ boiler while the E32 only watches it, or during the test; firmware without the test shows no block. Home Assistant has no button for it: the test needs someone at the boiler and the E32 page.

Without the confirmation nothing is sent. Another browser sees the test but has no Stop the test: only the person who started it can stop it there (the E32 also stops it by itself at any doubt). If Start is refused, the block says why: not confirmed in time, a test already running, the boiler busy, the thermostat still heard, the model already verified, a doubt since the start, or another boiler. Stay signed in on this page until the test is over: if your sign-in ends (signing out, or 30 minutes without any E32 page open), the E32 stops the test. The page reads the test every 5 seconds while it runs, but only while it is visible; keep it in front.

What the E32 does, in order:

1. Read: it asks the boiler for its maximum heating temperature, fresh, within 2 minutes.
2. No heat: it asks three times for no heat, 10 seconds apart. No flame for heating may burn now.
3. Heat: it asks for a low water temperature: 5 °C above the lowest the E32 uses, never above the boiler's maximum, the highest water temperature of your home, or 80 °C. It repeats the request for at most 10 minutes. This step passes when, within a minute, the boiler shows that target, the heating bit is on (if the boiler reports it), the flame starts within 5 minutes and the water to heating rises by 3 °C. It then keeps asking for 3 more minutes, so a hot tap can show that hot water still goes first.
4. Stop: it asks for no heat again, every 10 seconds. This step passes when the flame for heating is off within 2 minutes and the boiler's target is 5 °C or less, and both stay so for 5 minutes. A flame that stays on or comes back, or a target that stays above 5 °C, means the boiler has no clean stop.

Safety. At any doubt the E32 asks three times for no heat and ends the test at once. A doubt is: another thermostat asks for heat, the boiler is silent for a minute, the water pressure is below 1 bar, the water gets 15 °C warmer than asked, the boiler shows another target, the boiler gives the E32 no turn three times in a row, the E32's clock jumps back, or your sign-in on the E32 ends. You can stop it yourself at any moment. During the test the E32 accepts no other change, except stopping the test and signing out; Home Assistant's changes wait until it is done.

The result is one of: passed; no clean stop; not clear; failed; not started; not started (nobody confirmed); stopped. With it come the figures: how fast the boiler showed the target, how fast the flame came and went, the water temperatures and whether hot water paused the heating. A passed test makes My boiler say Tested by you: the result waits for review; the E32 does not control this boiler yet. until the next restart. "No clean stop" closes control for this boiler model on this E32. The result never changes the list of boiler models by itself: only a reviewed change does.

The test does not yet measure how long the boiler keeps a request without a repeat. The list uses 30 seconds for every EMS+ model.

What the E32 never sends to an EMS+ boiler #

• No boiler settings. Boiler settings work on EMS Classic boilers only, for now.
• No "heating off" setting as a way to stop. That setting is stored in the boiler; the E32 stops with a request for no heat.
• Nothing to thermostats, mixing modules or other devices on the bus.
• Only fixed messages: the request for heat or no heat, and fixed questions. Anything else cannot leave the E32.
• Only when the boiler gives the E32 its turn, and only under the E32's own bus address.
• No "no heat" to a boiler it never asked for heat.

The tester program and the path to Verified #

A boiler model becomes Verified through testers' results, not through code. The path, for one tester:

1. Keep the thermostat connected for a day, and check that the trial run looks plausible.
2. Disconnect the thermostat and wait 10 minutes.
3. Start the attended test, confirm within 60 seconds and watch for about 20 minutes.
4. Reconnect the thermostat.
5. Share the result (a passed test: asking for heat and stopping both passed) together with a bus recording.
6. The maintainers review it. Then a change sets that model to Verified in the list, with the result as its evidence. A firmware release carries the new list.

What the review needs:

Seven days of control by one tester are only possible once the owner decides that a tested boiler may be controlled before review. Until then, a model needs two testers.

Sharing. In Home Assistant, a tester ticks Take part in the tester program and chooses Share result. Home Assistant writes a summary file (the boiler's identity, the E32 and Home Assistant versions, the messages seen, the state of each value and the test results; boiler-share-<date>.json) and, when one is ready, the bus recording (boiler-share-<date>.emsrec.txt), into its www/open_thermostat folder. It sends nothing by itself. A notification lists what is in the files and links to a GitHub form, partly filled in. The tester attaches the files, adds a photo of the type plate and one of the boiler's display next to the E32 page, writes a line about what the boiler did during the recording, ticks the consent ("I share this recording under the project's licence") and sends it. The photos and the line are optional in the form, but the review cannot compare the recording with the boiler without them. An automatic check reads the files, posts one summary and labels the issue with the product number, the protocol and whether a test passed. A maintainer runs the same check (tools/emsplus/check_share.py). For the reading checks a recording of at least 25 of the 30 minutes is needed. The files hold no passwords, network addresses, Wi-Fi names or room names; the boiler's messages do hold room temperatures and the thermostat's clock. The switch is on the dashboard's Settings → Installation → Tester program (without the dashboard: Configure → Advanced and diagnostics → Tester program); the same screen starts and stops the bus recording.

The bus recording holds the newest 30 minutes of messages on the bus (the boiler's, the thermostat's and the E32's own), kept on the E32 in extra memory (PSRAM) that a restart empties. The tester starts and stops it. It listens, and keeps running during the boiler test and the attended test. It asks the boiler for one thing: its product number and version, when the recording starts and once more after 25 minutes (each time when the E32 may send, as for its other reads), so the recording holds the boiler's identity. When a recording lacks it anyway, the check takes it from the E32's own read in the summary file. Without that memory the recording is "not available". A very busy bus keeps a little less than 30 minutes.

What is not proven yet #

Nothing in this section has run on a real EMS+ bus yet. Everything is tested against recorded and made-up messages only. These points are open until testers' recordings show them:

• what each EMS+ value really means on each model, and the three-character display codes as real boilers show them;
• whether every EMS+ boiler gives the E32 a turn on the bus, and answers its questions about settings (a boiler that does not answer cannot be tested);
• whether a boiler confirms the E32's request, and whether 30 seconds is the right repeat and check time;
• whether a target of 5 °C or less is a real stop on every model (a Condens 7000i did not stop cleanly in another project);
• which faults lock the boiler;
• whether every boiler with product number 123 speaks EMS+, and which product number a Condens 7000i reports;
• the descriptions of three-character display codes: Home Assistant shows such a code without a meaning for now.

The four EMS+ models in the list today are product 208 (Buderus Logamax plus GB192, Bosch Condens GC9000, Worcester Greenstar ErP), 195 (Bosch Condens 5000i, Worcester Greenstar 8000, Buderus GB192i.2), 123 (Buderus GB172/GB072, Nefit Trendline, Bosch Cerapur, Worcester Greenstar Si) and 234 (Buderus Logamax plus GB122, Bosch Condens 2300, Junkers Cerapur GC2200W). All four are not tested. Another EMS+ boiler is read, and its shared recording helps to add it.

In Home Assistant #

• Boiler recognition: a diagnostic sensor on the E32 device with the five states Not recognised yet, Reading only, Tested by you, Verified and A different boiler. Its attributes give the product number, the boiler software version, the protocol, the model, the boiler profile, the control route, the reason (also in words), the sentence, whether it was confirmed since the start, the proven capabilities, the boiler settings verified and tested, and whether Home Assistant has the same list of models as the E32. The sensor appears only once the E32 reports it: with older firmware there is no sensor and no repair.
• The repair A different boiler is connected: "the E32 found a different boiler on the bus". Fix confirms the boiler now connected on the E32, as I changed the boiler does. The repair clears itself once the E32 knows the boiler again.
• Settings → Heating and boiler → Boiler model adds "Recognised on the bus:" with the boiler and its state. Choosing a model there still only names the boiler and picks its display code table.
• House and boiler on the Learning tab says the recognition sentence instead of "still listening", for a boiler the E32 may not control.
• The EMS+ values: nine more EMS+ values appear, as entities of the boiler: the display code, the cause number, heating active, burner rest left, the hot water 3-way valve, heating starts, heating on or off and hot water on or off (each with the name of its EMS Classic twin where there is one), and the status display information. Update Home Assistant before the E32: an older integration does not read the longer list.
• Take part in the tester program and Share result: see the tester program.

Backup and restore #

System → Backup and restore saves the settings of the E32 in one file: network and time (host name, time zone, time server), MQTT and the Home Assistant link, the room plan with its week programs, the planned holidays, the Bluetooth sensors, the water temperature settings, the boiler model, the radiator valves, the Shelly devices with their heating circuits, the switch for changing boiler settings and the page language. It also holds what the thermostat has learned about your rooms, so a replacement E32 carries on learning where the old one was. If that part of a backup cannot be read, the restore skips it with a note and the E32 learns from the start. What the E32 learned from your boiler (its ceiling and the boiler's rest, see listening to the boiler) is not in the file; a replacement E32 learns that again within days.

• Passwords and keys. By default the file holds no secret. The page lists what you need to enter again after a restore: the MQTT password, the OpenWeather key, the Bluetooth sensor keys and the passwords of the Shelly devices. The Shelly devices' webhook link is never in the file: the E32 you restore onto keeps its own or makes a new one and sets it up on the devices itself. Tick Include passwords and Bluetooth keys and choose a passphrase (12 to 64 characters; a backup with a shorter one, 8 or more, still opens) to keep them in the file, encrypted (AES-128-CCM, key from the passphrase with PBKDF2-SHA256). The Wi-Fi password and the web page password are never in the file.
• Restore on a new or reset E32: first connect it to your network (Wi-Fi setup or Ethernet) and sign in, then choose the file and Check backup. The E32 checks the whole file and shows what will change, what it skips and what you need to enter again. Nothing is saved until you choose Restore these settings. A backup without a passphrase holds no MQTT password, and MQTT stays off until you enter it again under System → Settings → Home Assistant. If saving one part fails, the E32 puts the earlier settings back. When network or Bluetooth settings change, the E32 restarts about 10 seconds later; sign in again afterwards. A restore that switches changing boiler settings back on says so in the check.
• What a restore never does. It does not change the Wi-Fi network or the port of the web page, it switches from Wi-Fi to Ethernet only while an Ethernet cable is connected and never from Ethernet to Wi-Fi, and it does not restore the takeover confirmation: the rooms keep the mode of the backup, but a new or reset E32 sends nothing to the boiler until you confirm the takeover on its Rooms page. A restore is refused while the E32 controls the boiler or a boiler test is running.

Automatic backups in Home Assistant #

With the Home Assistant integration you do not need to download files yourself. Once the E32 is connected (Configure → E32 connection), Home Assistant fetches the same backup file from the E32 every day, and once shortly after Home Assistant starts when the last backup is older than 24 hours.

• Passwords and keys are always included, encrypted with a random passphrase that Home Assistant makes once for this installation and keeps with the integration. You never type it. The Wi-Fi password and the E32 password are still never in a backup.
• Where they are. Home Assistant keeps them in its own .storage folder, so its own backups (Settings → System → Backups) contain them too: the newest backup of each of the last 7 days, plus the one made right before the last restore.
• On the E32 device in Home Assistant: the button Back up E32 settings now makes a backup at once, and the diagnostic sensor Last E32 backup shows when the last one succeeded (its attributes: how many backups are kept and the size of the newest).
• When it fails. If no backup succeeds for 3 days, Settings → Repairs shows No recent backup of the E32 settings. Check that the E32 is on and its web page opens, and that its password in Home Assistant is still right. The message goes away after the next successful backup.

To put a backup back: the dashboard's Settings → Installation → Restore settings to this E32 (without the dashboard: Configure → Advanced and diagnostics → Restore settings to this E32). Choose the backup by date, or (on the Settings tab) a Backup file saved on the E32 page with its passphrase. The E32 checks it first, and Home Assistant shows what changes, what is skipped and what you need to enter again. Nothing changes until you confirm. Right before the restore, Home Assistant also backs up the E32 as it is now. The rules are the same as on the E32 page. The rooms keep the mode of the backup; a new or reset E32 controls the boiler only after you confirm the takeover on its page (Boiler → Boiler test and takeover). A restore is refused while the E32 controls the boiler or a boiler test is running. When the network or Bluetooth settings change, the E32 restarts, and Home Assistant waits until it answers again.

Replacing a broken E32 #

1. Flash the firmware on the new E32 over USB, as for a first installation (see the README).
2. Join the network: connect the new E32 to your Wi-Fi with its setup access point, or plug in Ethernet, and note its address. Sign in on its web page once and change the default password (System → Password).
3. Connect it to the integration: in Home Assistant open Settings → Installation → Restore settings to this E32 and choose Another E32 (replacing a broken one) (without the dashboard: Configure → Advanced and diagnostics → Restore settings to this E32). Enter the new E32's address and password there. The old E32's saved password is never sent to another address.
4. Restore: choose the newest backup, read the summary and confirm (one question: these settings go onto the new E32, and Home Assistant uses it from now on). The E32 gets the network and time settings, MQTT and the Home Assistant link (with the MQTT password), the rooms and week programs, the Bluetooth sensors with their keys, the water temperature settings and the boiler model. It restarts, and Home Assistant links this installation to the new E32 (its address, password and identity). Your entities, history and dashboards stay as they were.

After the restore, enter what the summary lists (for example a Bluetooth key that was not in the backup). If the old E32 controlled the boiler, follow the switch-over procedure again before you confirm the takeover.

Logs and the diagnostics console #

System → Diagnostics and system log shows what the E32 is doing. It keeps the last 512 log lines in its external memory (PSRAM); they are gone after a restart. Filter by source (ESP or EMS), level or text, pause the view or download it.

Since 1.4 an address the E32 has no page for is one information line, "No page for /path (404)", instead of an error line without the address; the start-up line "nvs_open failed: NOT_FOUND" no longer appears.

Since 1.4.4, while the E32 has received device messages it could not read (a valve state that is too large, cut off or nested too deeply, or a message on a valve topic no valve has), the page says "Messages the E32 could not read: 3, last: zigbee2mqtt/…, too large (7.2 KB)", counted since the E32 started (Home Assistant's Diagnostics tab shows the same line under Connection with the E32). It is information, not a fault; to have such a device read, send a capture.

The page reads new log lines every 5 seconds and asks the E32 only for what it shows. Above the log is the line Last restart. Technical details holds the memory and stack reserves, the previous run, the loop timing and the time per loop part; these figures are read while the fold is open. The settings storage and the lowest free stacks take the E32 a little longer to gather, so they are read when you open the fold and when you press Read storage and stacks again (this also works while the log is paused); in between the line says when they were read.

The diagnostics console on the same page answers a fixed list of read-only commands. Type help for the list:

The console never changes a setting and cannot run anything else. Two actions sit below it, each with a confirmation: End idle web sessions signs out the browsers and Home Assistant sessions that have not been used for 2 minutes (yours stays), and Restart device. Neither runs during a boiler test, a boiler settings write or a firmware update.

The same data is available to scripts with a signed-in session: GET /status/diagnostics (all sections) or GET /status/diagnostics?section=memory,mqtt (sections: memory, tasks, nvs, mqtt, sessions, restarts, log), and GET /status/logs?tail=50. GET /status/logs sends its whole runtime block unless want= names the parts (intervals, previous, record, phases, memory, tasks, nvs; none for the log lines only); the Diagnostics page uses that from firmware 1.3 on.

Keeping logs after a restart: syslog #

The E32 can also send its log to a syslog server on your network (RFC 5424 over UDP). It is off by default. Under Logging settings on the Diagnostics and system log page, tick Enable syslog, enter the server's Syslog server IPv4 address and UDP port (usually 514), and choose the level. Messages that might hold a password, key or other private content are left out. The E32 sends at most ten messages a second and never waits for the server, so a slow or missing server cannot hold it up; dropped messages are counted on the page.

To receive the log next to Home Assistant, run a syslog server on any machine on your network: for example a syslog server app (add-on) in Home Assistant OS, rsyslog or syslog-ng on a Linux machine or NAS, or the log centre of your NAS. Give it a fixed IPv4 address and enter that address on the E32. Syslog over UDP is not encrypted and not acknowledged; keep it on your home network.

Tidy entity IDs (optional) #

Home Assistant gives every entity an ID, and some of OpenThermostat's are long. Settings → Installation → Tidy entity IDs (without the dashboard: Configure → Advanced and diagnostics → Tidy entity IDs) proposes the IDs Home Assistant itself would give these entities today, lists how many are used in your automations, scripts or dashboards, and renames them only after you confirm I have read the list and want to rename these entities. Under Which entities, Only entities that are not used anywhere is the safe choice. History and statistics move along, and the OpenThermostat dashboard follows by itself, but an automation, script or dashboard of your own that uses an old ID stops working until you change it; templates in YAML and other integrations are not searched. Entities you renamed yourself are skipped. Undo the entity ID tidy puts the old IDs back (where still free) for 30 days. A Dutch installation made with an early version may have IDs with the room twice (sensor.woonkamer_woonkamer_reden); this option offers to say the room once. New installations do so by themselves, and no existing ID changes by updating.