Problems after swapping T6360B for TP5000si thermostat

[stem]

There can be two faults with the tp5000si output. Remember it is just a switch, so even if faulty it will be either 'on' or 'off'. However, because the thermostat would be receiving its electrical supply from the programmer, even if the tp5000si were faulty it wouldn't result in....

I even went to the separate CH & HW programmer and switched the CH off from there but the boiler kept on running and wouldn't switch off!...

Because there wouldn't be any power going to the tp5000si for it to switch in the first place.

Is it possible something else was causing the boiler to fire? do you have a frost thermostat somewhere for example?

 

[Kieran42]

No separate frost thermostat... unfortunately for the time being I can't investigate the problem any further as soon as I turn the central heating system completely off rest of the family start complaining it's too cold!!... so may have to come back to it after the Xmas break or when the weather is a bit milder... mean time will have to stick with the old thermostat

Thanks again to all for your input... I will update the thread if I ever figure out whats going on!