Can not configure external sensor as thermostat

[hafgan250]

Hi,

at first thanks for this great work!!

My target: I have a new room temperature sensor and tried to use it as thermostat.

Integration Luxtronik => Configure the hub => Choose Sensor-ID (Shelly HTG3) => Success!

My Problem: But there is no actual room temperature (0°C). It seems, that the integration did not take it over, in fact. If I go back to the configuration, it requests me to configure the sensor again (with an empty field).

(The impact factor can not be changed (0), what is already #470 ). However, if I change the version to latest, I am still not able to configure anything #473 )

By the way, I can not even rename the hub. But is not of my concern at the moment. But may be releated.

(Version 2025.10.1)

[rhammen]

Does the entity name of the Shelly HTG3 start with "sensor." , or with something else?

[hafgan250]

Thanks for helping!

Sensorname: sensor.shellyhtg3_temperature

[rhammen]

@hafgan250 I have fixed #473 and #470 in the 'main' branch. When I then use that branch, I cannot reproduce (anymore) what you are seeing:

• I can change (configure) the temperature sensor
• That change of the room temperature sensor 'sticks'
• I did see once that the sensor initially showed 0 C, but after the next update (so like 30 or 60 seconds later), the temperature showed correctly the value of the configured temperature sensor.

My suggestion is therefore that you either try to test (manually install) the current main branch, or wait a couple of days for a new (beta) release that (hopefully) also solves the issue for your setup. Please report back once you have tested with the new version.

[hafgan250]

Thank you for your help!! I am impressed!!

I installed it manual in my testing environment. It seems to work:

• ShellyHTG3 sticks in the configuration
• It shows the actual temperature in the thermostat
• I can change the impact factor (and) it sticks!

Still questions:

• The entity of the actual room thermostat says 0°C (missunderstanding of my side?)
• If I change the target temperature and the impactfactor I see no change of the flow out temperature target. Do I have to switch it on in the Luxtronic? (RBE, Roomstation?)
• Is there any documentation about it?

[rhammen]

@hafgan250 Do you actually have a room thermostat specifically for your heatpump? The Heiz Raum Thermostat is lined to luxtronik caluculation "LC.C0227_ROOM_THERMOSTAT_TEMPERATUR". If it shows as zero, then my guess would be that either your system is not configured as having a room thermostat, or you have a different type of room thermostat that does not store the temperature in that calculation.

[hafgan250]

I understand, I do not have a special room thermostat. Therfore the "Heiz Raum Thermostat" have to be zero. Sorry for my missunderstanding.

Now the actual (22°C) and the target temperature (23°C) and the Impact (100%) show correct values. But the target "sensor.luxtronik_340306_0102_flow_out_temperature_target" should now be increased by 1°C. To achieve my setting of 23°C. I do not see that an increased flow target temp.

Still missunderstanding?

[rhammen]

The target room temperature is written to the luxtronik heatpump controller, and the control is done by the luxtronik controller. For this the the controller needs a (luxtronik) room thermostat, to know the current room temperature. (This is also why the impact factor in your case was originally set to 0% in your setup: that value is normally set by the room thermostat.) So without a luxtronik room thermostat, this will not work.

For now, you can influence the flow_out_temperature_target by changing the Heiz Ziel Korrektur.

In the past I had code in place that adapted the Heiz Ziel Korrektur based on the Home Assistant Room Thermostat target and the configured Room Temperature sensor. That would match your case. I may re-implement this in the future as a configurable option, because I am also not yet convinced that the flow_out_temperature_target correctly changes based on the current implementation. Maybe around Christmas time, when I have a couple of days off...

[hafgan250]

The target room temperature is written to the luxtronik heatpump controller, and the control is done by the luxtronik controller. For this the the controller needs a (luxtronik) room thermostat, to know the current room temperature. (This is also why the impact factor in your case was originally set to 0% in your setup: that value is normally set by the room thermostat.) So without a luxtronik room thermostat, this will not work.

OK, I got this! Thanks anyway!

For now, you can influence the flow_out_temperature_target by changing the Heiz Ziel Korrektur.

In the past I had code in place that adapted the Heiz Ziel Korrektur based on the Home Assistant Room Thermostat target and the configured Room Temperature sensor. That would match your case.

That was pretty much my expectation to use my shelly-htg3.

I may re-implement this in the future as a configurable option, because I am also not yet convinced that the flow_out_temperature_target correctly changes based on the current implementation. Maybe around Christmas time, when I have a couple of days off...

That would be wonderfull and much more than I ever thought!! Im no programmer, but if you need help I would try!

I already tried to calculate the correction and it seems to produce plausible values (but only calculation, no use of it):

    - name: heating_target_correction_test
      unique_id: "heating_target_correction_test"
      state_class: "measurement"
      state: >
        {{ float(((states('sensor.luxtronik_340306_0102_room_thermostat_temperature_target')|float(0) - states('sensor.shellyhtg3_temperature')|float(0))) * states('number.luxtronik_340306_0102_heating_room_temperature_impact_factor')|float(0) / 100) | round(1) }}