OpenTherm weather dependent heating control

[Maciek90]

Is this what you meant?

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{
	"Battery" : 255,
	"LastUpdate" : "2025-06-22 14:56:02",
	"RSSI" : 12,
	"description" : "",
	"dtype" : "Temp",
	"hwid" : "47",
	"id" : "145AE",
	"idx" : 1374,
	"name" : "In",
	"nvalue" : 0,
	"org_hwid" : "47",
	"stype" : "LaCrosse TX3",
	"svalue1" : "26.00",
	"unit" : 1
}

[akamming]

What do the general status and opentherm status of the main screen of the firmware show?

Could you also switch on the "Debug Messages to MQTT", and then post the output of the following command (make sure you do a restart after you typed this command):

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mosquitto_sub -t domesphelper/text/DebugToMQTT/state -u <your username> -P <your password> 

You should see something like:

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07:24:11 Configfile saved
07:24:14 Succesfully (re)connected, starting operations
07:24:15 Time was set
07:24:22 Received message on topic [domoticz/out/2019], payload: [{
        "Battery" : 255,
        "LastUpdate" : "2025-06-23 08:19:56",
        "RSSI" : 12,
        "description" : "",
        "dtype" : "Temp",
        "hwid" : "36",
        "id" : "0002",
        "idx" : 2019,
        "name" : "Ground Temperature (10 cm)",
        "nvalue" : 0,
        "org_hwid" : "36",
        "stype" : "LaCrosse TX3",
        "svalue1" : "16.3",
        "unit" : 2
}
]
07:24:22 First temperature (16.30) received, ready for climate mode
07:24:22 PID Mode, PID=(0.00,16.30,73.70), total: 90.00
07:24:23 PID Mode, PID=(0.00,16.30,73.70), total: 90.00
07:24:24 PID Mode, PID=(0.00,16.30,73.70), total: 90.00
07:24:26 PID Mode, PID=(0.00,16.30,73.70), total: 90.00
07:24:27 PID Mode, PID=(0.00,16.30,73.70), total: 90.00
07:24:28 PID Mode, PID=(0.00,16.30,73.70), total: 90.00

[Maciek90]

What do the general status and opentherm status of the main screen of the firmware show?

as in the picture below

Could you also switch on the "Debug Messages to MQTT", and then post the output of the following command (make sure you do a restart after you typed this command):

Code: Select all

14:31:59 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:00 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:01 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:01 Received message on topic [domoticz/out/1374], payload: [{
        "Battery" : 255,
        "LastUpdate" : "2025-06-23 15:32:02",
        "RSSI" : 12,
        "description" : "",
        "dtype" : "Temp",
        "hwid" : "47",
        "id" : "145AE",
        "idx" : 1374,
        "name" : "In",
        "nvalue" : 0,
        "org_hwid" : "47",
        "stype" : "LaCrosse TX3",
        "svalue1" : "27.00",
        "unit" : 1
}
]
14:32:02 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:03 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:05 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00

[akamming]

What do the general status and opentherm status of the main screen of the firmware show?

as in the picture below

Could you also switch on the "Debug Messages to MQTT", and then post the output of the following command (make sure you do a restart after you typed this command):

Code: Select all

14:31:59 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:00 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:01 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:01 Received message on topic [domoticz/out/1374], payload: [{
        "Battery" : 255,
        "LastUpdate" : "2025-06-23 15:32:02",
        "RSSI" : 12,
        "description" : "",
        "dtype" : "Temp",
        "hwid" : "47",
        "id" : "145AE",
        "idx" : 1374,
        "name" : "In",
        "nvalue" : 0,
        "org_hwid" : "47",
        "stype" : "LaCrosse TX3",
        "svalue1" : "27.00",
        "unit" : 1
}
]
14:32:02 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:03 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00
14:32:05 PID Mode, PID=(0.00,27.00,-17.00), total: 10.00

It’s working correctly. Your setpoint is set to 19. It recieves a value of 27 so the setpoint for the heating/cooling device is set to 10. What is the issue then?

[Maciek90]

Oh sorry, my mistake! I was looking at the Temperatures>Thermostat>-127 (like in the picture) readings. Now I know that the inside temperature works fine.
I have another problem. What about the outside temperature? I don't have a dedicated outside temperature sensor for the boiler. Until now, I used the sensor in Domoticz. In the plugin, I could provide its IDX. How can I currently use the sensor from Domoticz?

[akamming]

Oh sorry, my mistake! I was looking at the Temperatures>Thermostat>-127 (like in the picture) readings. Now I know that the inside temperature works fine.
I have another problem. What about the outside temperature? I don't have a dedicated outside temperature sensor for the boiler. Until now, I used the sensor in Domoticz. In the plugin, I could provide its IDX. How can I currently use the sensor from Domoticz?

outside temperature is the opentherm outside temperature (in other words: it will give a reading if you have an outside temperature attached directly to your boiler)

I understand your point: wasn't aware of it until now, but indeed since you could use any idx for outside temperature using the plugin. when you use the firmware itself as thermostat, you can only use the internal sensor. It is a good idea though, Maybe in the future i will add this capability.

[Maciek90]

Would you be so kind as to try to add this option before the heating season starts? I used the option with sensors in Domoticz in combination with the plugin and it worked very well. In the current situation I will have to buy an outside temperature sensor for the boiler.

[akamming]

I put it on my todo list. When I have Some time I Will add it…

[Maciek90]

In that case I'll wait patiently

[akamming]

In that case I'll wait patiently

i just updated the code, so you can now also use mqtt for the outside temperature.

it's not a setup i use for myself, so i could not test very well. Pls let me know if it works.

[Maciek90]

I'll try it in a few days.

[HvdW]

What is the difference between the ihormelnyk gateway and the nodoshop gateway?
Same functionality, different format?

[Maciek90]

i just updated the code, so you can now also use mqtt for the outside temperature.

it's not a setup i use for myself, so i could not test very well. Pls let me know if it works.

Something must be wrong. I've tried various sensors in Domoticz, and each one shows an outside temperature of 100 degrees Celsius. On the screenshot below I entered the same idx as for the inside temperature, because I am sure it works, but it also shows the outside temperature of 100 degrees, and it should show the same as the inside temperature.

[akamming]

i just updated the code, so you can now also use mqtt for the outside temperature.

it's not a setup i use for myself, so i could not test very well. Pls let me know if it works.

Something must be wrong. I've tried various sensors in Domoticz, and each one shows an outside temperature of 100 degrees Celsius. On the screenshot below I entered the same idx as for the inside temperature, because I am sure it works, but it also shows the outside temperature of 100 degrees, and it should show the same as the inside temperature.

You are using the same topic for inside and outside temperature. That is not correct. That should be a different one.

Fix that first and then let me know the results

[Maciek90]

Yes, I know I shouldn't use the same theme for both temperatures. I gave a bad example in the attached screenshot. I tried different IDXs and the situation was the same. I think the problem was elsewhere. My external sensor wasn't transmitting to Domoticz/Out, which is why I wasn't seeing the readings in the ESP panel. I think I managed to solve the problem and now I have readings for both the outside and inside temperatures.

However, I found another problem. In the previous software version, I could also control the options shown in the screenshot below from Domoticz. Now, in Domoticz, I can only control the Curvature option. The other settings didn't appear in Domoticz.

[akamming]

However, I found another problem. In the previous software version, I could also control the options shown in the screenshot below from Domoticz. Now, in Domoticz, I can only control the Curvature option. The other settings didn't appear in Domoticz.

It’s not a problem of the device. But it’s a limitation of domoticz which implementatis a mqtt number device a bit weird.

In domoticz It’s implemented as a Configuration item instead of as a controllable input. If you got to hardware, is a button “setup” on the mqtt ad line (at least i think, might also be called “settings”. In Dutch It’s “instellingen”). If you click it you can see “Configuration parameters”, which also invalide these settings.

[akamming]

Project Update: Now in Visual Studio Code!

I’ve migrated the esp_domoticz_opentherm_handler project from the Arduino IDE to Visual Studio Code. This change makes development and maintenance much easier, and brings all the benefits of VS Code’s modern environment.

Important:
If you want to use this code, please make sure to carefully follow the instructions in the README.md file. The setup and build process is now different from the Arduino IDE, and the README contains all the necessary steps and dependencies.

Feel free to ask questions or share feedback!