Please excuse my ignorence, but I know nothing about boilers and I hope someone can give me some indication of what could be wrong with my boiler.I have an old Halstead boiler (gas combi) which has given us some trouble with lockouts before, but after reset it has always been okay. Today our hot water has stopped working altogether, but the central heating still works. There is no red lights showing and we have tried switching it off and on, and resetting it. From this brief description, can anyone have a guess was is wrong and how much it might cost to get fixed, or even better... suggest a way we can get our hot water to work?Thanks in advance.
First off check the system pressure on the gauge on the front of the boiler is showing 1bar when cold as sometimes this can be a problem and can also cause it to lockout. If that is OK then as has been suggested its probably the diaphragm in the diverter valve, thats the bit that tells the boiler hot water or heating. When it fails then all you get is heating(usually). I would suggest an engineer is best suited for this job,
Could well be the diverter valve micro switch or the diverter valve itself
Well, usually you can start diagnosing it by putting your hand on the various pipes to figure out what's not flowing. If the boiler water is hot, then you need to follow the piping into the exchanger (typically a hot water tank where pipes from the boiler coil through heating your domestic water that runs out to the tap). Make sure any valving is open, etc...
Firstly I don't think you have a combi boiler (I apologise if wrong). Combis supply hot water on demand straight to a hot water tap without storing it in a hot water cylinder. The incoming cold water mains provides the flow as opposed to a pump. The pump is to circulate the hot water around the radiators. But no matter, you have a three way valve which reacts to the demands of a room stat and a cylinder stat. The fault is somewhere in the HW electrical circuit including the three way valve. You could check that the HW cylinder stat is clicking on and off. Apart from that it would be quicker and maybe cheaper in the long run to get a heating engineer to check it out. Plumbers are good at plumbing (usually) but not as competant as heating engineers as the latter have to know all about CH electrics. I would ask British Gas Services to fix it, and sign up for maintenance. All boilers break down, but BGS will attend 24/7.
