Hot water OK, CH not working!

[Andy-H]

I have a Potterton Promax combi 28HE Plus A.
Hot water fine, heating not working. If I remove the diverter motor and press the valve manually, the radiators heat up!
I have replaced the motor (diverter valve) and the PCB. The thermostat is a Danfoss wireless RET B-RF conected to a Danfoss RX 1. Which seems to be working correctly.
(i.e. setting therm. Lights RX1). But still no CH. !!!!
Can anyone please help??

 

[Deleted member 120897]

Not sure why you’d replace the pcb without due cause. Pressing the pin down on the diverter valve give some you CH and you have replaced the motor, that leaves the valve itself - have a look at replacing this (some are cartridge type).