In Cooling mode changes in Thermostat Parameters are not sent back correctly to the physical Thermostats (and the bosch app)

[MarkusMas]

DESCRIPTION

Hello, first off, I’m new to the ems-esp project and would like to thank everyone involved.

When my heatpump switches to cooling mode, none of the parameters of the room thermostats (from ems-esp UI/ or HA UI) are applied/ send back correctly to the heatpumps room thermostats.

On the other hand all changes made on the physical room thermostats and in the bosch app are correctly reflected in the ems-esp data.

REQUESTED INFORMATION

systembackup/ config

{
   "system":{
      "version":"3.8.2",
      "uptime":"000+00:15:15.610",
      "uptimeSec":915,
      "resetReason":"Power on reset / APP CPU reset by PRO CPU",
      "platform":"ESP32",
      "cpuType":"ESP32-D0WD-V3",
      "arduino":"ESP32 Arduino v2.0.17",
      "sdk":"v4.4.7-dirty",
      "freeMem":171,
      "maxAlloc":107,
      "freeCaps":4160,
      "usedApp":2378,
      "freeApp":2294,
      "partition":"app0",
      "flash_chip_size":16384,
      "psram":true,
      "psramSize":4093,
      "freePsram":4022,
      "model":"BBQKees Electronics E32V2.2 rev.2.2/2026012",
      "txpause":false,
      "gpios_allowed":"2, 4, 5, 14, 32, 34, 36, 39",
      "gpios_in_use":"2, 4, 5, 14, 32, 34, 36, 39",
      "gpios_available":""
   },
   "network":{
      "network":"Ethernet",
      "hostname":"ems-esp",
      "TxPowerSetting":0,
      "staticIP":false,
      "lowBandwidth":false,
      "disableSleep":true,
      "enableMDNS":true,
      "enableCORS":false
   },
   "ntp":{
      "NTPstatus":"connected",
      "enabled":true,
      "server":"time.google.com",
      "tzLabel":"Europe/Berlin",
      "timestamp":1780499322,
      "NTPStatus":"connected"
   },
   "ap":{
      "provisionMode":"disconnected",
      "ssid":"ems-esp",
      "security":"wpa2",
      "channel":1,
      "ssidHidden":false,
      "maxClients":4,
      "localIP":"192.168.4.1",
      "gatewayIP":"192.168.4.1",
      "subnetMask":"255.255.255.0"
   },
   "mqtt":{
      "MQTTStatus":"connected",
      "MQTTPublishes":749,
      "MQTTQueued":0,
      "MQTTPublishFails":0,
      "MQTTReconnects":0,
      "enabled":true,
      "clientID":"esp32-e0077000",
      "keepAlive":60,
      "cleanSession":false,
      "entityFormat":1,
      "base":"ems-esp",
      "discoveryPrefix":"homeassistant",
      "discoveryType":0,
      "nestedFormat":1,
      "haEnabled":true,
      "mqttQos":0,
      "mqttRetain":false,
      "publishTimeHeartbeat":60,
      "publishTimeBoiler":10,
      "publishTimeThermostat":10,
      "publishTimeSolar":10,
      "publishTimeMixer":10,
      "publishTimeWater":10,
      "publishTimeOther":60,
      "publishTimeSensor":10,
      "publishSingle":false,
      "publish2command":false,
      "sendResponse":false
   },
   "syslog":{
      "enabled":false
   },
   "modbus":{
      "enabled":false
   },
   "sensor":{
      "temperatureSensors":1,
      "temperatureSensorReads":182,
      "temperatureSensorFails":0
   },
   "analog":{
      "enabled":true,
      "analogSensors":3,
      "analogSensorReads":11,
      "analogSensorFails":0
   },
   "api":{
      "APICalls":0,
      "APIFails":0
   },
   "bus":{
      "busStatus":"connected",
      "busProtocol":"HT3",
      "busTelegramsReceived":6115,
      "busReads":1320,
      "busWrites":0,
      "busIncompleteTelegrams":0,
      "busReadsFailed":0,
      "busWritesFailed":0,
      "busRxLineQuality":100,
      "busTxLineQuality":100
   },
   "settings":{
      "boardProfile":"E32V2_2",
      "locale":"de",
      "txMode":1,
      "emsBusID":13,
      "showerTimer":false,
      "showerMinDuration":180,
      "showerAlert":false,
      "hideLed":false,
      "noTokenApi":false,
      "readonlyMode":false,
      "fahrenheit":false,
      "dallasParasite":false,
      "boolFormat":1,
      "boolDashboard":1,
      "enumFormat":1,
      "analogEnabled":true,
      "telnetEnabled":true,
      "maxWebLogBuffer":50,
      "modbusEnabled":false,
      "forceHeatingOff":false,
      "developerMode":false
   },
   "devices":[
      {
         "type":"boiler",
         "name":"XCU_THH/CS5800i, CS6800i, WLW176i, WLW186i",
         "deviceID":"0x08",
         "productID":8,
         "brand":"Bosch",
         "version":"00.00",
         "entities":182,
         "handlersReceived":"0xBF 0xC6 0xD1 0xE3 0xE4 0xE5 0xE9 0x0494 0x0495 0x048F",
         "handlersFetched":"0x14 0xE6 0xEA 0xEB 0x02CC 0x048D 0x04A2 0x0485 0x0486 0x0492 0x0488 0x0484 0x048B 0x0491 0x0499 0x049C 0x049D 0x04AE 0x04AF 0x04AA 0x02D6",
         "handlersPending":"0x10 0x11 0xC2 0x15 0x1C 0x18 0x19 0x1A 0x35 0x16 0x33 0x34 0x27 0x2A 0x28 0x02E0 0x048A 0x04A5 0x04A7",
         "handlersIgnored":"0xE7 0x02EA 0x061E 0x023E 0x0240 0x0291 0x0292 0x0293 0x0294 0x029B 0x02A5 0x02F5 0x04A8 0x04A9 0x04AB 0x04AC 0x04CA 0x04CB 0x04D8 0x04F2"
      },
      {
         "type":"thermostat",
         "name":"HMI800.2/Rego 3000, UI800, Logamatic BC400",
         "deviceID":"0x10",
         "productID":253,
         "brand":"",
         "version":"47.09",
         "entities":80,
         "handlersReceived":"0x06 0x02BA 0x02BB 0x02BC 0x031D 0x0267 0xBF 0xC0",
         "handlersFetched":"0x02A5 0x02B9 0x02AF 0x029B 0x0471 0x0467 0x0291 0x0292 0x0293 0x0294 0x02F5 0x023A 0x0240 0xBB 0x023E 0x016E",
         "handlersPending":"0xA3 0xA2 0x12 0x13 0x02A6 0x02B0 0x029C 0x0472 0x02A7 0x02B1 0x029D 0x0473 0x02A8 0x02B2 0x029E 0x0474 0x02A9 0x02BD 0x02B3 0x029F 0x0475 0x02AA 0x02BE 0x02B4 0x02A0 0x0476 0x02AB 0x02BF 0x02B5 0x02A1 0x0477 0x02AC 0x02C0 0x02B6 0x02A2 0x0478 0x0421 0x0422 0x0468 0x0423 0x0469 0x0424 0x046A 0x02F6 0x031B 0x031E 0x0269 0x0470",
         "handlersIgnored":"0x0507 0x0508 0x0509 0x050A 0x059D 0xF7"
      },
      {
         "type":"heatpump",
         "name":"HP Module",
         "deviceID":"0x38",
         "productID":252,
         "brand":"",
         "version":"14.00",
         "entities":0,
         "handlersPending":"0x047B 0x0998 0x0999 0x09A0 0x099B 0x099C 0x04AE 0x04AF 0x099A 0x012E 0x013B 0x04AA",
         "handlersIgnored":"0x0A5D 0x0C5B 0x1683 0x0A5B 0x0C59 0x1681 0x045D 0x0A57 0x0A58 0x0A59 0x0A5A 0x0A5C 0x0A5E 0x0A5F 0x0A60 0x0A61 0x0A62 0x0A63 0x0A64 0x0A65 0x0A66 0x0C5D 0x1685 0x0C5C 0x1684 0x0C55 0x167D 0x0C57 0x167F 0x0C5A 0x1682 0x0C56 0x167E 0x0C58 0x1680 0x16E1 0x16E2 0x16E3 0x16E4 0x16E5 0x16E6 0x16E7 0x16E8 0x16E9 0x16F5 0x0C5E 0x0C5F 0x0C60 0x0C61 0x0C62 0x0C63 0x0C64 0x0CAF 0xBF"
      },
      {
         "type":"gateway",
         "name":"K40RF/MX400",
         "deviceID":"0x48",
         "productID":17,
         "brand":"Bosch",
         "version":"14.00",
         "entities":0,
         "handlersIgnored":"0xF9 0x2040 0x0495 0x0494 0x04AF 0x04AE"
      },
      {
         "type":"gateway",
         "name":"K40RF/MX400",
         "deviceID":"0x4B",
         "productID":17,
         "brand":"",
         "version":"14.00",
         "entities":0,
         "handlersIgnored":"0x04D6 0x04D7 0xBF"
      },
      {
         "type":"connect",
         "name":"K40RF/Wireless base",
         "deviceID":"0x50",
         "productID":17,
         "brand":"",
         "version":"14.00",
         "entities":64,
         "handlersReceived":"0x0BDD 0x1244 0x0BDE 0x1245 0x0BDF 0x1246 0x0BE0 0x1247 0x0BE1 0x1248 0x0BE2 0x1249 0x0BE3 0x124A 0x0BE4 0x124B 0x0BE5 0x124C 0x0BE6 0x124D 0x0BE7 0x124E 0x0BE8 0x124F 0x0BE9 0x1250 0x0BEA 0x1251 0x0BEB 0x1252 0x0BEC 0x1253",
         "handlersFetched":"0x0B3D 0x0BB5 0x1230 0x0B3F 0x0BB7 0x1232 0x0B40 0x0BB8 0x1233 0x0B41 0x0BB9 0x1234 0x0B42 0x0BBA 0x1235 0x0B43 0x0BBB 0x1236 0x0B44 0x0BBC 0x1237 0x0B45 0x0BBD 0x1238",
         "handlersPending":"0xD1 0x06 0x0B3E 0x0BB6 0x1231 0x0B46 0x0BBE 0x1239 0x0B47 0x0BBF 0x123A 0x0B48 0x0BC0 0x123B 0x0B49 0x0BC1 0x123C 0x0B4A 0x0BC2 0x123D 0x0B4B 0x0BC3 0x123E 0x0B4C 0x0BC4 0x123F 0xDB65",
         "handlersIgnored":"0x2040 0xBF"
      },
      {
         "type":"temperaturesensor",
         "name":"temperaturesensor",
         "entities":1
      },
      {
         "type":"analogsensor",
         "name":"analogsensor",
         "entities":3
      }
   ]
}

About my Heatpump and setup:

• Heatpump: Bosch CS5800i
• with build in Controller: UI800
• Communication Module: Connect Key K40 RF
• Regulation of individual rooms (DE: "Einzelraumregelung") by Bosch SRC 100 RF (equivalent to Buderus SRC plus)
• Bosch Thermostats THIW 230 in each room
• Two rooms are linked as one group (SRC1 + SRC2)
• Thermostats automatically switch between heating and colling mode when needed (all at ounce)

TO REPRODUCE

• set heatpump to cooling mode (or let it set itself)
• in the EMS-EPS UI or Homeassistant:
  • try changing room temperature or
  • try changing the thermostat operating mode: auto (schedule), manual, off

==> Changes in cooling mode do not appear on physical room thermostats/ nor in the app.

However i noticed, that the changed parameters are instead applied to the heating mode, which is inactive/ hidden (in the bosch app) at this point. So it seems that he parameters are not send correctly.

EXPECTED BEHAVIOUR

I would expect, that the changed "selected room temperature" and "operating mode" would be applied correctly to the cooling mode as well as to the heating mode.

[MarkusMas]

Seems someone indeed came across this issue before

#1781

but i assume it was not fixed due to inactivity.

[proddy]

there was nothing to fix (not a bug) and closed 1.5 years ago. If you want we can re-open the thread. It does need follow-up and investigation by the users to locate the data

[MarkusMas]

Hi @proddy, thank you for having a look at this issue.

Can you please explain, why you think there is/ was nothing to fix?

To me this very much looks like a bug, because from the ems-esp (and home assistant) i will have no control over the room temperatures (thermostats) while the heat pump is in cooling mode (perspectivly half of the year).

I will be happy to contribute, if you could please tell me how (i'm new to this project).

[MichaelDvP]

When my heatpump switches to cooling mode, none of the parameters of the room thermostats (from ems-esp UI/ or HA UI) are applied/ send back correctly to the heatpumps room thermostats.

ǹone` is very unspecific. As we don't have heatpump and SRC devices, we need exact infos to change anything.
For the SRC all we know is from #2636. And cooling was unclear and can't be tested in october (see: #2636 (comment)).

Start a log with log level all and change the parameters (that are not correctly in ems-esp) on the thermostat or on the bosch app, Tell parameter and values and time, so we can find the change in the log. Maybe we are able to identify the right telegrams/offsets.

[MarkusMas]

@proddy i had a look at the logs and the option to add custom entities to the ems-esp.

Using the bosch app and changing the temp to 22°C while in cooling mode results in this event beeing logged:

gateway(0x48) W connect(0x50), Roomsettings(0x0BB5), data: 2C (offset 6)

And when changing the selected room temperature from the ems UI (to 22°C):

2026-06-04T10:42:59.714 I 15923: [command] Called command connect/seltemp (selected room temperature) with value 22 and id 36 on device 0x50
...
2026-06-04T10:43:00.266 T 15932: [emsesp] me(0x0D) W connect(0x50), Roomsettings(0x0BB5), data: 2C (offset 3)
...
2026-06-04T10:45:07.638 T 16759: [emsesp] me(0x0D) R connect(0x50), Roomsettings(0x0BB5), length: 8
2026-06-04T10:45:07.713 T 16760: [emsesp] connect(0x50) W me(0x0D), Roomsettings(0x0BB5), data: 01 2E 00 2C 01 FF 2C 00

So to me it looks like the ems-esp always changes the value at offset 3. However when in cooling mode it looks like the value at offset 6 should be changed (as the bosch app does)

I hope this helps :)

[proddy]

Thanks Michael. @MarkusMas we didn't classify it as a bug only because this logic is simply not implemented for these devices. We started investigating with one user (see #1781 (comment)) but that thread went stale. Now we have you we can continue!

[MarkusMas]

And additionally currently the operating mode is not changed correctly:

Using the bosch app and changing the operating mode (to auto) in cooling mode results in this event beeing logged:

2026-06-04T11:17:20.664 T 29577: [emsesp] gateway(0x48) W connect(0x50), Roomsettings(0x0BB5), data: 00 (offset 4)

And when changing the operating mode in the ems-UI (to auto)

2026-06-04T11:18:51.670 I 30153: [command] Called command connect/mode (operating mode) with value auto and id 36 on device 0x50
...
2026-06-04T11:18:56.850 T 30218: [emsesp] connect(0x50) B all(0x00), Roomsettings(0x0BB5), data: 00
...
2026-06-04T11:19:29.893 T 30413: [emsesp] me(0x0D) R connect(0x50), Roomsettings(0x0BB5), length: 8
2026-06-04T11:19:29.957 T 30414: [emsesp] connect(0x50) W me(0x0D), Roomsettings(0x0BB5), data: 00 2E 00 2C 00 FF 2C 00

Here i think in cooling mode the operating mode should be changed in offset 4 (as the bosch app does). Instead of the offset 0.

btw: i just want to make that clear: the "oprating mode" is not the state of heating or cooling. this option is about: auto (heating/colling according to a schedule); manual (fixed temp); off. This was discussed here: #2636 (comment)

I hope all this makes sense to you too :)

[MichaelDvP]

Here i think in cooling mode the operating mode should be changed in offset 4 (as the bosch app does). Instead of the offset 0.

That is strange,please try the other modes too. In #2636 (comment) the modes are clearly written to offset 0.

I hope all this makes sense to you too :)

Not much. A log and some more changes would be helpfull. I don't know what was set before you changed the mode and can not see the state in offset 0 when offset 4 was changed.

I've made a change in https://github.com/MichaelDvP/EMS-ESP32/releases, still mode in offset 0, but add back cooling again and seltemp writes to coolingtemp if mode is set to cooling (not working if mode is from wrong offset). Please check.

[MarkusMas]

Hi @MichaelDvP,

there seem to be two destict thermostat settings that require a different offset depending on the "heatpump operating state" (heatin/ cooling). One is the "selected temperature" of each individual thermostat and the other the "operating mode" (auto/ manual/ off) of each individual thermostat.

Some more values for the operating mode:
when "operating mode" is set to "manual" (heating/ cooling according to a fixed target temp), the value is 01. For heating mode at offset 0 and for cooling mode at offset 4.

And from my previous message:
when "operating mode" is set to "auto" (heating/ cooling according to a schedule), the value is 00. For heating mode at offset 0 and for cooling mode at offset 4.

Edit: corrected mixup in values

[MarkusMas]

I don't know what was set before you changed the mode and can not see the state in offset 0 when offset 4 was changed.

A change in offset 0 does not affect a change in offset 4 and vise versa. These are the sepearte operating modes of the individual thermostat.

The operating state of the actual heatpump (heating or cooling) automatically "sets" all the thermostats to cooling or heating mode at once. (There is no option to switch between heating or cooling from the actual thermostat!!!) And then the stored values are uesd accordingly.

While in heating mode:
operating mode from offset 0
selected temp from offset 3

While in cooling mode:
operating mode from offset 4
selected temp from offset 6

At the moment the ems-esp always writes the values to the "heating mode" in offset 0 and offset 3. Instead there should be some kind of evaluation of the operating state of the heat pump (heating or cooling mode) and then in cooling mode, the values should be written to offset 4 and 6.

Hope that explains my thoughts a bit clearer.

[MarkusMas]

The values for usage in operating mode (offset 0 and offset 4) are:

00 = auto (heating/ cooling according to a schedule)
01 = manual (heating/ cooling according to a fixed target temp)
03 = off (this thermostat will be deactiveted)

[MichaelDvP]

I have asked two times for a log and still did not get one.
The values 0, 1, 3 for offset 0 are clear since long time, but the values for offset 4: 0 for heating and something other (WHAT?) for cooling. What are combinations of of offset 0 and 4?

offset 0 - offset 4 = meaning
00 - 00 = auto heating
00  - ?? = ??
01 - 00 = manual heating
01 - ?? = ??
02 - 00 = ?? 
02 - ?? = ?? 
03 - 00 = off
03 - ?? = ??

This is my last try, than i give up.

[MarkusMas]

As stated before: A change in offset 0 does not affect a change in offset 4 and vise versa. These are the sepearte operating modes of the individual thermostat depending on the operating state of the heat pump (heating or cooling).

The possible values for offset 4 are basically the same as for offset 0. With values as mentioned here: #3107 (comment)

• The values in offset 0 are used while the heat pump is in heating mode
• The values in offset 4 are used while the heat pump is in cooling mode

I am very much trying all i can do to explain the situation to you. And i have given you all the information i am able to give to you at the moment.
If you think you still need logs - despite my detailed explanation - i will be happy to send some to you. But unfortunately at this very moment i am not able to generate full log files. Please let me know.

[MarkusMas]

btw: I have now tested forcing the heat pump (from cooling mode) back into heating mode.

Doing that results in no change in the room settings data (for example: connect(0x50) W me(0x0D), Roomsettings(0x0BB5), data: 00 2E 00 2C 00 FF 2C 00)