potterton suprima 50l not starting

[pwilbur]

Hi
Potterton suprima 50l is not starting tries then eventually red light locks out, fan running, air pressure and flow switches all ok. Can hear gas valve operating. Can't hear or see ignition sparking, there is 120volts AC at the electrode permantley is this correct, I am guessing its a pcb fault, but hoping for clarification before spending all that money. Any advice appreciated.
Cheers
Paul

 

[powell30]

First bit of advice......don't open the combustion box.

Second.....call an rgi