MTS-100 thermostatic valves: Specify auxiliary temperature sensor to override TRV temperature readings

Is your feature request related to a problem? Please describe. The MTS-100 TRV built in temperature sensor is heated by the radiator itself and gives crazy readings which prevents me from controlling temperature in the room ie. it says the current temperature is 24 °C after 30 minutes of heating while the room was only heated to 20.5 °C.

Describe the solution you’d like Ability to control the following settings of the TRV:

• cold_tolerance
• hot_tolerance
• target_sensor (that would replace the built-in thermometer in the TRV)

Describe alternatives you’ve considered Is there any way to expose the YAML code for the entities created by your integration and add the following code? cold_tolerance: 0.8 hot_tolerance: 0 target_sensor: sensor.my_auxiliary_thermometer

EDIT: I’m able to specify “ambient_temperature” parameter on the frontend to display actual temperature in the climate entity but the TRV doesn’t seem to use this reading to start/stop heating.

Additional context Sorry if I’m dumb and missed something just there’s no wiki to explain how to do that.

[ertechdesign]

For the time being I was able to create a workaround directly in Home Assistant as @krahabb advised.

The main issue is generic thermostat only accepts a switch entity as a heater. My workaround was to create a switch that will control the Meross TRV.

Here’s my code for configuration.yaml:

• Please populate [SWITCH_NAME] with any name you want
• Please populate climate.[MEROSS_TRV_ENTITY] with the name of your existing Meross TRV climate entity name.
• Please remove the square brackets. (examples: My_Switch_1, climate.Meross_TRV_SH3215)

switch:
  - platform: template
    switches:
      [SWITCH_NAME]:
        turn_on:
            service: climate.set_temperature
            data:
              temperature: 25
            target:
              entity_id: climate.[MEROSS_TRV_ENTITY]
        turn_off:
            service: climate.set_temperature
            data:
              temperature: 15
            target:
              entity_id: climate.[MEROSS_TRV_ENTITY]

• Please populate [THERMOSTAT_NAME] with the name of the new Thermostat
• Please populate switch.[SWITCH_NAME] with your selected switch name above
• Please populate sensor.[AUXILIARY_THERMOMETER] with any thermometer that you want to control your TRV with.
• Please remove the square brackets. (examples: My_Thermostat_1, switch.My_Switch_1 , sensor.ble_ORIA_DC75225_thermometer)

climate:
  - platform: generic_thermostat
    name: [THERMOSTAT_NAME]
    heater: switch.[SWITCH_NAME]
    target_sensor: sensor.[AUXILIARY_THERMOMETER]
    min_temp: 15
    max_temp: 25
    ac_mode: false
    cold_tolerance: 0.8
    hot_tolerance: 0

Now you can replace the Meross TRV with climate.[THERMOSTAT_NAME] in Home Assistant Front-End and control your TRV with Generic Thermostat.

Advantages:

• The TRV stops giving false reading during heating
• You can use any thermometer you want that is supported in Home Assistant
• You can easily set minimum temperature, maximum temperature, hot and cold tolerance for advanced control.
• The TRV stops randomly adjusting the radiator 20 times a minute (this woke me up after a night out and annoyed me a lot)

Disadvantages:

• I now have 8 thermostats for 4 TRVs (only 4 are exposed in the Home Assistent UI, the original TRVs are no longer required to be exposed)

Principle of the solution:

• When the generic thermostat starts heating, the TRV is set to 25 °C and gets fully opened
• When the generic thermostat stop heating, the TRV is set to 15 °C and gets fully closed

[krahabb]

This is very well done! Awesome 😃