bean away for 2 yrs, returned home to fill system up and hoped to operate boiler.several occassions the boiler would fire up for short period of time before going out whilst indicating air in the system.pump is newish and operating okay,hot water thermo okay, 3 way valve old and supect however tryed manually position.the boiler now refuses to fire up and the 1 amp fuse on the pcb board has blown,hence i have tryed to replace but blows each time.any advice would be appreciated,the boiler is 20+yrs.THANKYOU.

C.WILKINSON, July 2007

I believe this model is now obsolete and i seem to recall a memo which circulated some 2/3 years ago that major repairs involving opening the combustion chamber renders the appliance illegal, or at least puts its safety in question.This was apparently to do with not being able to replace the casing seals or some safety issue with the products of combustion(carbon monoxide).
Never had the need to check this info because i have'nt seen one in ten years that was still working.
Chances are, it's the fan that is blowing the fuse, and you would need someone registered to open it up to find the true fault.
It may be easier to ring potterton and ask if they still do spares and check the validity of repairing it in respect of casing seals etc.

T.h.s, July 2007