Hi guys (if anyone is reading this over xmas). I had the nice present of my boiler breaking on christmas eve! Oh joy. I'm getting no hot water or central heating and the fan/flue fault (50°C) light is flashing. I know there are similar threads on here and I've read through a few of them and read the service manual, and the fault finding procedure is: 1. check electrical and pressure tube connections 2. check for blockages in pressure tubes 3. check for restriction in flue 4. check venturi and if those are ok replace air pressure switch, but I've read a lot of posts saying it could be a PCB problem. The fan does a couple of rotations when I first turn the hotwater on and then stops, if that is a clue to what's wrong. My first question is what, if any of that can I do myself as a DIYer (I've previoulsly replaced a hotwater diaphragm and hotwater sensor if that's any indication of my skill level). I'm not interested in doing anything that might put my family at risk for the sake of saving a few bob, but if I can avoid paying £200 to get someone out then that would be good. I'm assuming I can't touch the flue or the venturi because they involve going inside the combustion box. Thanks in advance.