ComfoAir - Pre-Heater control parameter P52


the excellent protocol explanation ( ) used as the basis for the ComfoAir binding is great but not complete.

I would like to integrate further functionality and need someone with a working control unit (mine is broken) and a serial connection to the main unit to sniff the communication between the control unit and the main unit in order to identify the command required to set the control parameter used to fine tune the optional pre-heater.

I know that only one of the two (control unit / binding via serial connection) should be running / connected at the same time in order to avoid conflicts but its no problem for a short period.

As described in the protocol explanation document mentioned above, the E1 command is used to READ some parameters. The payload of the E2 response contains 6 bytes, of which the last byte is the parameter I would like to modify.

It is parameter P52 of the main unit defining the sensitivity of the pre-heater. It is used internally by the main unit together with some other parameters (incoming air temperature, comfort temperature, type of heat exchanger module,…) to control activation and possibly power level of the pre-heating module.

So, what do I need?

I simple protocol of the communication between the control unit and the main unit while P52 is modified using the control unit.

Anyone willing to help?

BTW: You do NOT actually need to have such a pre-heater installed in the main unit. P52 should be modifiable anyway using the control unit.