Grateful for any advice! Boiler will suddenly cut out, and attempt relight. Will continue to go through this cycle until it finally lights. Cycle includes brief ignition sequence, which normally fails.From reading other articles, it sounds like a pressure switch issue, or PCB failure.

I've checked rubber hoses - and basic function of pressure switch - seems to work when small aire pressure applied, but that's just by me blowing into it !

Can I diagnose in any other way?

Thanks !

Stuart

Stuart Monger, May 2005

i had the same problem with mine, it ended up being the wiring harness to the main pcb on the front aparently a common problem on these but i didnt find out what the problem was untill it buggered my pcb up and they are ££££ but the wiring harness is not expensive part only £15 wish i found this out before it knakered my pcb,

paul, November 2008

Think I've found the solution. HT leads were arcing onto metal PCB backing plate. Ordered new leads, but taped up old ones. Seems to work fine.

Stuart Monger, May 2005