Nest 3 wire diagram

[Sinex666]

combi boiler

Excluding the wire to the 12v terminals, what’s going on here, help appreciated

i can work out

Blue to N

Brown L

1

2

Black to 3

4

Grey to 5

[Sinex666]

Blue to N

Brown L

1 Free clear 

2 to L via U link

Black to 3

4 to 2 via U link

Grey to 5

[Frustratedddd]

That's for a Combi boiler?

Not a system boiler with Hot Water, correct?

What exactly is your question?

Who ever installed it needs to look at the most important wire, the Earth!!!

What do you have in these terminals, not colours but where do they go or come from?

N = Neutral Supply

L = Live Supply

1 = ?

2 = ?

3 = ?

4 = ?

5 = ?

6 = ?

[zoeuvre]

Hi folks, 

Thanks for chiming in, @Frustratedddd. 

@Sinex666, thanks for posting here in the Community forum and for showing interest in our Nest Thermostats. Are you located in North America or Europe? And what is the make and model of your thermostat? On the other hand, you may use our Compatibility Checker to determine if a Nest Thermostat is compatible with your heating and cooling system.

Keep us posted. 

Best,

Zoe