Boiler not shutting off. I think it's because a Grundfos pump is stuck on since smart meter install.

[JonnyH12]

OK thanks for that, as suspected one of your zone valves is calling for heat, either a seized synchron motor , or a stuck micro-switch, as the heat is getting away from the boiler I suspect a seized botor, in your first pic you have two zone valves (silver boxes) these have a little manual lever on the side , turn heating and HW off and try and slide the manual lever across to the manual position, both should show resistance, if one doesnt show resistance that is your fault

Right!! Thank you so much for your help.

So the bottom silverbox, which I believe is for the HW, has resistance. The top one, does not. It's totally lose. It lights up if I turn the CH on, but you're saying that the internal motor is probably busted?

Should I replace the whole valve or is there osmething internally i can replace?

Thanks!

 

[ianmcd]

Right!! Thank you so much for your help.

So the bottom silverbox, which I believe is for the HW, has resistance. The top one, does not. It's totally lose. It lights up if I turn the CH on, but you're saying that the internal motor is probably busted?

Should I replace the whole valve or is there osmething internally i can replace?

Thanks!

yep that is indeed your problem, you can either replace the actuator (the silver box) or the synchron motor, they are honeywells so easy to do and you have plenty of room there so wont be hard, just make sure you isolate the power when doing either as there is a permanent live in there so live even when you switch the heating off, lots of videos on youtube showing how to change both

 

[JonnyH12]

yep that is indeed your problem, you can either replace the actuator (the silver box) or the synchron motor, they are honeywells so easy to do and you have plenty of room there so wont be hard, just make sure you isolate the power when doing either as there is a permanent live in there so live even when you switch the heating off, lots of videos on youtube showing how to change both

Right I've just played around with it and it's almost certainly the motor, I am pretty sure its jammed. I will get out and replace it now. Does this box do anything except control the valve, does it pump or anything similar?

 

[ianmcd]

Right I've just played around with it and it's almost certainly the motor, I am pretty sure its jammed. I will get out and replace it now. Does this box do anything except control the valve, does it pump or anything similar?

The way the system works, when you select HW or heating, power is sent to the corrosponding motor, the motor opens the valve, when the valve is fully open it makes a small micro switch, this switch powers the boiler and pump, the motor has seized in the made position, hence why the pump is constantly running and the boiler is firing, your programmer only powers the motor , everything else is done by the valves