Thank you very much for your replies. The service was thorough, by a contractor that I know and trust. The fan does start ok but sometimes it is a bit noisy as if it is grating on the casing. If you spray it with WD40 and adjust the rubber mountings then it seems to spin smoothly.
Can anyone help? This boiler will not light unless you take off the front cover to get more air to the boiler or you hold a piece of cardboard over the flue for a few seconds which seems to build up pressure and forces the boiler to light.
Two separate heating engineers have looked at this...