Chaff SE80

Attended a Breakdown of a Chaff SE80 Symptoms:Locking Out No sparking. Cleaned Fan up cleaned all terminals around APS as plastering recently carried out, carried out a full clean up got going ok CH & DHW Temps ok left running for a couple of hours no problem. Been back 3 times same problem but i manage to get it going after a reset etc. Checked all terminals,connections everything seems ok, but keeps locking out, fan runs APS OK not stuck tubes clean and fan venturi all seem ok, suspect PCB? Any hints on these fabulous appliances. do not want to commit for fear of appliance having same problem.

I have recently become aware that few people ever check the pressure from the ventury or the actual pressure that the APS operates at.

Equally few people check the APS contact resistance or even know what it should be!

The flame detection electrode and lead also need checking too.

Tony

it was the pcb