Automate your Bosch Thermostat 2

Automation especially for the Bosch Thermostat II (BTH-RA)

One of the big advantage of the Bosch TRV is that it’s possible to set the value of an external temperature sensor as current temperature – there is no need of the usual manual calibration. I was surprised that nobody published an automation for the sync of the external temperature sensor. So I tried to build up a blueprint on my own. That’s my first one btw. :nerd_face:
Please give it a try if you own a Bosch Thermostat II.

(Btw. I also tried to sync a window sensor with the window_open entity analogues to the external temperature sensor, but sadly the TRV will forget the target temperature after a few minutes and it keeps a low target temperature after closing the window. So I ended up in the typical solution of setting the TRV off/on depending on the window sensor)

Core Features

  • Switch the TRV on/off depending on a window sensor
  • Sync the value of the temperature sensor to the TRV’s internal remote_temperature entity (there’s no need to calibrate it manually via local_temperature_calibration)
  • Based on a weather entity and a winter temperature the TRV will be switched off to avoid heating in the summer


  • Maybe this blueprint works also for other TRVs. The required entity of the TRV: remote_temperature
  • The blueprint is currently only tested with z2m – maybe someone can verify it for ZHA.



  • Add time based trigger for temp sync
  • Make window sensor optional
  • Add error handling if the remote_temperature entity is missing


Open your Home Assistant instance and show the blueprint import dialog with a specific blueprint pre-filled.


A good blueprint but i think you should trigger that at least every 30min because if the temperature will not update every 30mins it will use the internal sensor again.

Thanks for your reply. That’s a good idea, I will test a bit. Maybe that can explain why the TRV keeps heating even though the target temperature is already reached.

Hey, I’ve been trying to implement your Blueprint but the Trace tells me that the “Template rendered invalid entity IDs” at the last step of the Automation

service: number.set_value
  value: '{{ states(current_temperature) | float }}'
  entity_id: '{{ remote_temperature_entity }}'

Actually it seems that your TRV don’t have the internal entity called “remote_temperature”. What kind of TRV did you setup as thermostat? Really a Bosch Thermostat 2?
But never the less I really need to implement some error handling.

Yes they are Bosch Thermostat 2. Can’t figure out why I can’t call remote temp

are you using via ZHA or Z2M? I don´t know if the entity is there in ZHA

Any chance to use this Automation without the need for the window sensor?
We have a bathroom that has no windows and the automation needs a window sensor.
Or should I resort to rebuilding it? :slight_smile:

I never thought about that. This is of course a valid use case. I’ll make the input optional.
But you there is an easy workaround, so you can use the blueprint now: Just create a template for a sensor for the non existing window and set it permanently to “off” to indicate it as closed window.

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Very ture. I didnt think of that simple solution :smiley: Thanks for the heads up :slight_smile:

For that I just built a quick node red automation, that triggers all of my TRV Automations every 5 minutes. Works like a charm.
The external Temp is always up to date.

@Mar1us Done. I added the time trigger and updated the blueprint.

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