Hi,
It appears that my boiler is not working correctly. I get hot water through the taps and shower no problem at all, but when i switch the central heating on the radiators fail to heat up and it appears that no water is circulating through the system. The boiler sounds like it should normally but other than that nothing.
Any pointers or help would be greatly appreciated as to the problem or cause and how to rectify the issue.
Regards

Mark, September 2009

one likely suspect in your case is the motorised valve that opens up when heating is switched on. this will be kocated on the flow pipe to radiators, outside , but nearby the boiler

tariq, April 2011

Had a look at boiler last night after work. When central heating is switched on the boiler fails to fire up. When hot water from taps is demanded the boiler ignites although i watched it several times and on couple of occasions the flame stopped and was then reignited. The boiler model is Vaillant VCW-GB-242E.

Mark, September 2009

You say that the Boiler is firing normally but no heat?

Do you have Thermostatic Radiator Valves?
are the valves turned up high enough to open, or are the pins on them stuck shut?

I was working in a solicitors office in Cambridge yester day 36 Radiators 32 had stuck TRV's!!

www.elanar.co.uk, September 2009