Got part fitted it and no change still not igniting. Called Biasi for recommendation of local RGI. Called in recommended engineer and explained the saga thus far. Within 10 mins he followed trail to ignition PCB and tried out new replacement PCB which he had available, boiler fired up first...
Many thanks guys for the feedback. I should have the new APS sometime today, I'll fit it and see how it goes. If it doesn't fire up then I will call in a RGI as recommended.
Also forgot to say once I removed the switch I tested it for continuity when blowing down the clear tube attached to the switch. The switch does switch and the contacts open an close as expected. Hence I am a little worried the switch itself is ok! Assistant in the spares shop did say they are...
Got a Biasi combi boiler "M90e.28s" which will not ignite. Problem is the same whether switching on for hot water or central heating. The fan turns accelerating, there are quite a few clicks going on sounds like contact opening/closing..... there is no ignition i.e. no flames, then the fan power...