Combi boiler not heating water: Any ideas?

[northerner]

Still have central heating, just no hot water. It's only hot for about 3 seconds, then stone cold.

Dh thinks it can't be a major problem as radiators are still working so is not into calling out a plumber as it will be expensive.

Any help appreciated. Thanks.

This happened to us over Christmas, was imagining expensive plumbers etc but the next day all was fine again. I did look on the net and there's a website called Preloved which has a section about repairing boilers - have a look there.

Yes, it's some sort of switch thing (air switch?? I can't remember what he called it!) that's meant to trigger the boiler when a hot tap is run. The switch has a rubber seal thing and this wears meaning the seal is intermittant/non existant the the switch doesn't work. Happened to ours.

Was it expensive to fix soupy?

I can't remember - it was 18 monnths ago and was done at the same time as a service. Not massively expensive I don't think - maybe £100? Boiler repairs are never cheap

I think it was maybe called a pressure switch BTW