Boiler issue

matymck

Had new 3 port valve motor fitted to boiler heating/hot water system at home. Caused fuse to blow. Plumber then changed the complete 3 port valve with alternate to original. Boiler firing when time programme wasn't on. Electrician called and started reconfiguring wiring arrangement and then changed timer programme clock. Now heating will not turn on when thermostat and timeclock on, however it will if the hot water is or has just been on. I think there maybe some sort of cross connection with boiler pump overrun timer as on both hot water and heating when turned off the pump also instantly stops running but before all this it didn't. Any ideas?

Le_Kirk

I think you are right in that "there maybe some sort of cross connection" and the only way to find it is to get your service people back and ask them to sort it out.  I had an instance last year where the 3-port valve had a fault and the boiler kept firing despite the position of the programmer.  Not suggesting you have a faulty valve but it can easily be incorrectly wired.  Without seeing the system wiring, I doubt you will get a solution on the forum.