Thermia heatpump - Understanding the sensors and behaviour

Hi all,

I’m using the thermiagenesis custom integration created by @CJNE . Thank you for this great integration, saved me a lot of time.

The integration allows me to take control of my heatpump and define setpoints & operating modes in a more dynamic way.

At this moment, I’m trying to understand the heatpump’s behaviour, as well as trying to understand the meaning of the many sensors that come with the integration.
This leads to some questions:

  • As you can see in the screenshot above, the room temperature is always at 0 °C, and the room temp setpoint is 21 °C. I don’t understand why this is not showing the currect room temp.
  • During the night, the heatpump doesn’t operate to heat the house, and typically at 5h in the morning the heatpump starts operating again.
    I have been looking at the “system supply temperature”, which seems to be above its setpoint during the night. That could explain why the heatpump is not running then, but it’s strange to see that the “system supply temp” remains above setpoint without the heatpump generating heat.

    Underlying question is: I’d like to understand this process, and therefore I’d like to know which temperature sensor is measured where in the installation.

Anyone who also has the Thermia heatpump and using the integration, who could help out?
Thanks in advance.

1 Like

I’m glad that you have found some use for the integration!
For your first question, the room temperature sensor is not always installed, are you sure you have one?
I don’t have it and I also have 0 for room temperature.

Your other question is a bit trickier, do you mean that system supply line temperature increases without the heat pump running? It would be interesting to see a graph for heat pump selected gear for the same time period.

Newbie here - where can I find this integration? Thermia doesn’t seem to be listed under Integrations.

My technician told me this is rarely installed. The heat pump simply checks the difference in temperature between the water going in and coming back (return valve). If that’s bigger than value X, it continues to heat.


I just started playing around with the ThermiaGenesis integration. Thanks for this fantastic tool!

I have a question for CJNE:

In the integration, there are two sensors called ‘sensor.high_pressure_side’ and ‘sensor.low_pressure_side’. They show temperature in degrees celsius.

Looking at the Modbus manual for Thermia Genesis, I find on Pg13 ‘Input registers, function 4’ following: High pressure side, pressure (bar(g)), addr 127 and Low pressure side, pressure (bar(g)), addr 128.

My question: Should the ‘sensor.high_pressure_side’ and ‘sensor.low_pressure_side’ not have bar(g) as units?


I am working on a picture elements card containing some of the sensors; still figuring out a lot and learning along the way.

Best regards,


Here is what I am working on:

Will be happy to share if I can get it to work :slight_smile:

Hi Rogy,

Did you get the interface working? :slight_smile:
Might also want to use it for my Thermia Kalibra 7

Kind regards,