I've just started getting a problem with my potterton combi 80. The hot water side works perfectly well. When I turn on the central heating the boiler fires up for about 10-15 seconds then turns off. There appears to be a large amount of air coming out of the air vent that is not present when the hot water is working. The system was working okay before I went to sea a few weeks ago, but has not been on for about 4 weeks. Does anyone have any ideas of what my next step could be?
Many thanks
Many thanks