I have a Baxi Combi 80e boiler. Wouldn't you know it. Just as Christmas is approaching the boiler starts playing up. I get hot water but when I try and turn the heating on the orange 'Burner On' light keeps coming on and trying to light and then goes out again. Can anyone shed any light on this problem and is a DIY fix or am I going to have to be ripped off by a gas engineer at this time of year. I'm not saying they are all rip off merchants but I've been stung in the past