If the fan is running it could be the aps safety device of even pcb. Can't tell without being there, other than from your brief description it will need an RGI in to look at it I'm afraid because of the possible safety implications.
Internal 4amp? Do you mean the spur switch in which case itsh usually 3amp. Are you qualified to touch a boiler? Messing with something that has gas and electric is highly dangerous, thats why we have strict laws in place.
However I do know alot of industry qualified fitters who can put a boiler on the wall but don't know there a*** from there elbow when it comes to repairing one.
How old is your boiler? Is it still under warranty?
thanks for the replys fully understnd working with gas and have always used corgi reg fitter. to answer your question not under warranty. have had this problem before thought it might be simple as a fuse this is what led me to this site next move is to get the yellow pages out and ring a plumber THANKS FOR YOUR REPLIES
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