when hot water is required the potterton performa starts but the burner does not come on,sometimes it seems to work especially in the morning and very very late at night. During the day the water sometimes works when turned on mostly only cold water comes out but no hot water as requested.

benny, June 2009

common performa/main problem is pcb, boiler starts up fan spins and it looks like air pressure switch is not making and therefore not starting ignition but generally its pcb.
Rule out a.p.s first of course and thats based on the impression the fan spins, if fan spins, aps is ok, then pcb.
Doddle to do, 10 mins tops. Power off!

q, June 2009