24cdi flame failure - maybe

A corgi local mate has just changed a holed diaphragm in one of these which was fine on CH.
Afterwards, CH light slowly flashing indicating flame rec or pcb. Main burners light then it goes to lockout very soon. Once it flashed before even trying to light. Doesn't know what he could have done to the pcb but changed it.
Exactly the same. Then he called me!
Electrode resistance checked back to a pad on the board , nice and low.

Um.

I once had a similar thing , which was cleared by wiggling the board connector - is there something which could have been knocked?

Bad earths are the only thing I've since thought of, to look at.

Ditto Chris, its only my experience, but i have had similar problems in the past, with Worcesters, esp CDI range.

The wiring looms , especially were they join the connectors , suffer from dry joints.

I know its a pain, test every wire back, for continuity. ( not teaching you to suck eggs , and all that )

Best of luck.

Dave.

Call out Worecester. If its locking out before running the fan etc its a board fault. At the price of a new board and fitting its cheaper for the customer to call out manufacturer - was about £220 fixed price.

Chris I know you will have checked but what is the mains gas pressure like?. I had one the other week with a blockage in the gas main, it would build up enough pressure in the main to light for a few seconds then the pressure would run out and lose rectification....would be a hell of a coincidence mind you.

A tiny droplet of water in the multiway connector?