It started earlier this year after a power failure. THe hot water was OK but the boiler would not fire up for central heating. We pressed reset, turned it on and off a few times, and it came back on and then same thing happened again later. All was working well til yesterday and I thought I would attempt to programme the timer for the first time since it was installed to save money in the winter gas bill. Then I turned the termostat up and there was no central heating ! So I cancelled all the timer settings and there is still no central heating but there is hot water. I've tried reset, mains on and off, and tried ON or OFF or AUTO on the timer and have cleared all programmes but it's not having it this time. The thermostat clicks in but the boiler doesn't fire up. AND I AM GETTING COLD !!! Any help appreciated ....