Nest

[WhoMe?]

Hi

About 2 months ago we had a neat fitted and UFH with its own thermostat. The CH did work when it was first installed but with it being summer it was left unused. Now the Nest does not appear to be firing up the boiler. The green dot is on the heat link which means they're connected. The UFH works and the how water works. The zone valve on the UFH works but the one for the CH does not appear to be. There's resistance to the switch and it makes a kind of revving noise when pushed.

Can anyone tell from the above what it could possibly be?

Thanks

 

[ianmcd]

you need to check for voltage between the brown and blue wires on the ch zone valve when there is a demand for ch, if 230v then you have a faulty zone valve actuator

 

[Deleted member 267285]

Try pushing the override on the heat link, I’ve read and heard about these heat links failing, and if it has it might not be sending the switched live out.

 

[WhoMe?]

Try pushing the override on the heat link, I’ve read and heard about these heat links failing, and if it has it might not be sending the switched live out.

Thanks but that did not do anything.

Weird how it worked at first and not now

 

[Deleted member 267285]

Thanks but that did not do anything.

Weird how it worked at first and not now

Sounds like a failed heat link, and yes they can just fail. If you want the heating on and you’re confident you can join the 2 wires up inside (providing it’s not the 2/3 port).

 

[muggles]

Thanks but that did not do anything.

Weird how it worked at first and not now

Things break I agree with Ian, likely to be a failed zone valve motor

 

[WhoMe?]

The installer is coming back on Monday. I'll wait until then. Thanks all

 

[WhoMe?]

Turns out brown wire was not connect in little white terminal box and the thermostat wire in the boiler was in the wrong port.