UK Nest e thermostat wiring question

[Mattressback]

Hi just bought a nest e thermostat . Ive included a picture of the wiring for the old thermostat and the connections for the new nest thermostat. I just want to make sure it’s compatible before I get someone to install it. Which wire goes to which connector for want of a better question ?

 

[telectrix]

seems you need a N which you've not got in the existing stat.

 

[buzzlightyear]

I just want to make sure it’s compatible before I get someone to install it

I would agree with Tele ,and would agree with your self .

 

[Midwest]

Does seem unusual not to have a neutral at an old existing room stat. Someone moved the existing stat in the past?

 

[buzzlightyear]

Does seem unusual not to have a neutral at an old existing room stat. Someone moved the existing stat in the past

possible that is a two wire system .

 

[Mattressback]

Is N neutral?

Gas was only installed about ten years ago

 

[telectrix]

you need a 3core/E cable instead of the T/E.

 

[James]

The nest thermostat is a combination of time clock and thermostat.
The base “receiver” unit can be fitted next to the boiler where there will be all the cables that you require.
The control or thermostat unit would normally be placed wherever the old thermostat is mounted and only needs 2 cores. This is to supply power from the base unit to the stat unit, as per the instructions.
All the control signals are sent wirelessly from the stat to the base unit.

Although this could be done by someone good diy skills and electrical knowledge, I would recommend getting a professional in to do it.

A mistake in the wiring could do any of the following.
1. Write off the boiler control board
2. Write off the nest thermostat
3. Cause a shock or other injury
4. All of the above at the same time.

As long as you have a wire with at least 2 cores going from the boiler to the old stat, a professional should have you up and running within the hour.

P.s. for the techs reading this, the only function of the link wire from base unit to stat is to supply 12v dc to the stat for its own power.

 

[Mattressback]

Hi again, can I just clarify that this is a nest thermostat E that uses the heat link at the thermostat with nothing fitted to the combi boiler itself (obviously the thermostat connects to the boiler at that point). I’ve just spoken to nest tech support and told her that I only have a 2 wire system and she seemed very confident that they will connect to the C and NO and that the system will work.

 

[telectrix]

Is N neutral?

Gas was only installed about ten years ago

N is indeed neutral.
[automerge]1568132889[/automerge]

The nest thermostat is a combination of time clock and thermostat.
The base “receiver” unit can be fitted next to the boiler where there will be all the cables that you require.
The control or thermostat unit would normally be placed wherever the old thermostat is mounted and only needs 2 cores. This is to supply power from the base unit to the stat unit, as per the instructions.
All the control signals are sent wirelessly from the stat to the base unit.

Although this could be done by someone good diy skills and electrical knowledge, I would recommend getting a professional in to do it.

A mistake in the wiring could do any of the following.
1. Write off the boiler control board
2. Write off the nest thermostat
3. Cause a shock or other injury
4. All of the above at the same time.

As long as you have a wire with at least 2 cores going from the boiler to the old stat, a professional should have you up and running within the hour.

P.s. for the techs reading this, the only function of the link wire from base unit to stat is to supply 12v dc to the stat for its own power.

so, if i read your right. ( bear in mind i have no knowlege of nest), he needs a 3core/E (or 4 core flex) from boiler to receiver, and just a pair to the actual stat., which mus be RF to the base unit?

 

[buzzlightyear]

I’ve just spoken to nest tech support and told her that I only have a 2 wire system and she seemed very confident that they will connect to the C and NO and that the system will work.

op I would ask the people at nest to sort you out .

 

[Mattressback]

I’ve just found this installation video. Is this not exactly my combination of wires brown, blue and yellow/green

5mins 50 in..

 

[telectrix]

with your existing stat, brown is L, blue is switched L. Gn/Y is earth.there is no neutral.

 

[Mattressback]

Oh , now my head is hurting, I won’t even pretend I understand and now beginning to think I’ve wasted my money , thought this was going to be an easy swap over

 

[James]

Nest e is far simpler than the original nest unit.

Download the app, the app will guide you through installation.
All the info is here, watch the video, pause it when you need to do something, then continue.

https://store.google.com/gb/product/nest_thermostat_e?gclid=EAIaIQobChMIhevLsurG5AIVzbHtCh3pYAEVEAAYASAAEgJLMvD_BwE&gclsrc=aw.ds

If you are unsure, get a professional in to assist.

 

[Mattressback]

Yeah I’m going to get a professional to do it for me, he’s doing it as a favour so I really wanted it to be as simple as possible and that’s why I bought the E . It’s also a housing association property so if it’s going to require a neutral wire installed then I’m probably going to require permission and other red tape before I can go ahead which will probably lead me to just not doing it.

I’m curious to know why telectrix knows it’s a switched live and not a neutral as every website I’ve looked at says neutral is a blue wire. Is it to do with the wiring diagram I uploaded?

 

[westward10]

You need to ignore the fact it is blue the installer should have put brown sleeve over it.

 

[buzzlightyear]

It’s also a housing association property

have you written permission from them to alter the wiring for the nest .

 

[Mattressback]

No that’s why I said it would hold things up. I’ve been told if I fit a nest they won’t maintain it and would only replace it with basically what’s in now .

 

[buzzlightyear]

most housing associations dont like people playing with their boilers or other things just in case their is a mishap .