Yes, thanks to the great advice on here, I managed to get my boiler going again by replacing the PRV and expansion vessel. Bolier is working perfectly except for one thing. The front panel requires a gentle tap for the bolier to ignite when the central heating is timed to come on. I figure its a problem with the PCB and wonder if this is fixable or just buy a new PCB. (Bosch part no 87161023390). Could it be a dry joint or a faulty relay or anothe component. My friend is an electronics engineer to trade so if these are replaceble what is it like to be. Any you guys got suggestions?