Help me identify room stat wire? Nest

[Echo the husky]

The room thermostat cable is connected to the white wire of the valve. The wiring is rather poor especially at the programmer.

 

[DavidL1983]

Thanks Echo..

Is it something I should get looked at? I've only lived in the house a year. It all works ok I suppose.

 

[stem]

Whilst it's not a brilliant example, it is representative of many installations, and I have seen much worse. If the wires are securely fixed in the terminals and there aren't acres of copper on show it should be OK. The earth terminal is a bad example that could be tidied up. There are probably too many earth wires in a single terminal, so you may find it easier to provide two earth terminals. Linked together of course.

Because the Nest carries out the functions of the room thermostat, the old wired thermostat needs to be 'non functioning' to prevent it overriding the Nest. This can be done in three ways, in order of preference, they are.

1. Find the other end of the thermostat cable and disconnect it. Then link the terminals where the two switching wires came from together. Echo is right, the white wire will be one of them. [The white wire is normally associated with a 3 port motorised valve and indicates that you probably have a 'Y Plan']

2. Remove the existing thermostat and replace it with a junction box, connect the two switching wires together and isolate the earth

3. Leave the existing room thermostat in place and set it to the highest setting. (Or put the two switching wires together in the same terminal)

 

[DavidL1983]

Thanks stem. I've had a pro come round and sort it out along with fitting the Nest. All sorted now. Thanks