My Baxi 100 HE is giving me big trouble. The ignition sequence is accompanied by a massive bang (sometimes a series of 3 or 4 in quick succession) and, more often than not, the lockout light comes on. This has been intermittent for some time but in the last few days has become very frequent. Now its stopped the bang and just locks out after 3 or 4 failed ignition sequences. Any tips before I end up spending big money?

Julian, October 2009

you need a new burner, depending what one you have (depends on age) there will either be a hole in the fibre burner or the ceramic plate will have become detached. DO NOT USE THE BOILER UNTIL FAULT HAS BEEN FIXED, otherwise you will do serious damage to the rest of the boiler. I'd suggest calling British Gas, or similar and asking for a fixed price repair, as the burner is an expensive part.

Ian, October 2009