DIY Doctor UK DIY Forums

Advice
Boiler has developed fault wont fire up when CH only set fire up for few seconds then red light comes on. If i reset run hot tap it fires up if I then switch on central heating it stays lit turn tap off and it still stays lit. will just not fire up by switching central heating on first.

Unlikely any one on hear can help, I don't know boilers well enough, however you would need to give make and model of boiler, system used Y-Plan etc, and fuel used oil or gas to have a chance.

If you had not said red light, I would have guessed at faulty three port valve, and would have suggested moving the bleed level and latching as a temp fix, but that fault should not have lit a red light.