Boiler was installed just 3yrs ago. For more than a year has had an irratic fault when boiler doesn't switch off at end of programme, or during programme when required temp is reached. This used to happen occasionally, but now nearly all the time. Display on boiler reads 6 74-81. Does this mean a problem with the control system? The 'heating and gas' company who installed boiler says it is an electrical fault, the electrican who wired the programmers etc says it is down to the plumbers. Obviously, neither of them want to get involved. Another electrician (not a CH expert) thought it may the PCB. I'm not at all technical and will need to call in someone who understands such matters. Does this sound like a problem with the boiler, or could it be something to do with the wiring that an electrican could sort out? It seems electrical as it is not using any gas when the boiler overrules the programmes. I think Zone One serves the CH in main house and HW, and Zone 2 the underfloor heating in the conservatory. Any suggestions would be much appreciated, please.
