Need help to increase/decrease the set thermostat temp based on the variance with a separate temp sensor

Configuration
1

Hi Clever People,

I have some rooms fitted with Honeywell evohome TRVs set up in the following way in HA: climate.kitchen, climate.bedroom and so on. Currently the schedule/target room temp is managed via evohome (for now!), however I am noticing a variance between the room temp that the TRVs are saying it is vs an aquara temp sensor (which follow a convention of Sensor.room_temp…etc).

For example, the room is set to heat to a target of 20 degrees, the TRV is saying that the current temp is 18 degrees whereas the aquara is suggesting the room temp is 23 degrees. How do I calculate the delta and then change the target heat up/down by the variance between aquara and the target evohome temp - in this case reduce temp by 3 degrees? I should add that the aquara automation will have a setting of 20 degrees as the max temp it will want a room to heat to.

Thanks in advance - I hope this makes sense as I am very new to HA.

2

I think I have a workaround using thresholds to “manage” the challenge.

3

This is how I finally resolved the issues. Works well and allows you to override the TRV sensor and use a 3rd party room sensor.

Better Thermostat