Nest 2nd gen thermostat help

bettz1 · 26 Apr 2022

Hi I've been changing our kitchen socket switches to brushed metal ones and on Sunday I changed the fuse switch for the boiler.

Turned off the main fuse board took a picture of the wiring and went and changed the socket.

Now we've noticed the nest thermostat has gone off at the wall and the lights no longer on at the heat link.

So I've switched the sockets back to how it was but still no luck.

Any ideas?

The nest is saying No power to RH wire & then heat link connecting, which fails then says the power to the thermostat is off..

ianmcd · 27 Apr 2022

How is the nest thermostat powered ? by USB or by the receiver ? are you sure when you swap the wires over you are not connecting onto the wiring insulation instead of the conductor

bettz1 · 27 Apr 2022

ianmcd said:
How is the nest thermostat powered ? by USB or by the receiver ? are you sure when you swap the wires over you are not connecting onto the wiring insulation instead of the conductor

The thermostat is powered by the heat link. I can charge it myself via USB but it only lasts an hour or two.

Turned the boiler fuse off all night and decided to check the wires in the socket to make sure they were seated properly, one of the blue wires felt loose, turned it all back and the bloody thing has powered up again

I'm now a bit anxious about putting the replacement fuse socket back on.

Nintendofan · 27 Apr 2022

new build house by any chance? I can see that the metal back box hasn't been earthed.

ianmcd · 27 Apr 2022

bettz1 said:
one of the blue wires felt loose, turned it all back and the bloody thing has powered up again

Well that is your problem you need to make the connection correctly.

bettz1 said:
I can charge it myself via USB but it only lasts an hour or two.

I using the USB it needs to be plugged in all the time if not wired to the receiver , it is the power source , it is not there to charge it up

bettz1 · 27 Apr 2022

Paulj48 said:
new build house by any chance? I can see that the metal back box hasn't been earthed.

Yep new build house, is that something I could do?

nitro23456 · 27 Apr 2022

Its fine, the screws earth it to the backbox.

Nintendofan · 28 Apr 2022

nitro23456 said:
Its fine, the screws earth it to the backbox.

Its lazy and bad practice, belt and braces approach is always best if the option is there.

nitro23456 · 28 Apr 2022

Maybe so, but there is no requirement to do so under the regs as long as the back box has atleast one fixed lug which it has.