Nest 3rd gen heat link wiring connections?

[aubrey4444]

I'm interested in installing a nest 3rd Gen in my house now it can cope with Hot water and heating. Had a look at the current setup which is a Honeywell Timer for Hot water and Heating which seems to be wired as follows.


so the first pic is what i had so i just wired in the new heat link the same it turns on and connects to the stat but no power to boiler?

 

[Johnmdc]

Link L to 2 and 5
Brown to 3
White to 4
Black to 6
The nest has knock outs on the back of it to bring your wires into it so they are safe and not on view.

 

[aubrey4444]

Link L to 2 and 5
Brown to 3
White to 4
Black to 6
The nest has knock outs on the back of it to bring your wires into it so they are safe and not on view.

Hi

Sorry what do you mean

Link L to 2 and 5 ?? Move which wires

 

[aptsys]

Move which wires

You should not have single insulated cables exposed so you need to move the wires to be completely enclosed in the unit. There are some knockouts at the back which will allow you to drop the unit 15mm and not have this issue.

Terminal 2 should be connected to terminal 5.

 

[aubrey4444]

You should not have single insulated cables exposed so you need to move the wires to be completely enclosed in the unit. There are some knockouts at the back which will allow you to drop the unit 15mm and not have this issue.

Terminal 2 should be connected to terminal 5.

Again sorry what do you mean ?

Do you mean the 2 live wires in L should be moved to TER 5? as there is 1 brown 1 red?

And yes i will use the 2 Knockout to enclose the wires

 

[stem]

First of all you cannot just swap the wires over 'number for number' because they are different products from different manufacturers and do not correspond. Were there not instructions
with the Heatlink explaining what each terminal does? Like this.



Anyway, it's good that you took a photo of the original wiring. The wires at your original programmer were as follows:

N= 'Neutral' Blue & Black wires
L = 'Live' Brown and Red wires
1 'Hot Water Satisfied' = White wire
3 'Hot Water Call for Heat' - Black wire
4 'Heating Call for heat' = Brown wire

The good news is that the N and L will be correct as you have moved them, so if you look at the diagram for the Heatlink you will see which terminals correspond to the others. In fact johnmdc has already told you.

Brown to 3
White to 4
Black to 6

You also need to link the L terminal to terminals 2 and 5, again as already advised.

The main difficulty comes if you have an existing wired room thermostat, which will need decommissioning, so that the Nest can take full control of the heating. Unfortunately it can't just be disconnected otherwise the heating won't work. If you do have an existing room thermostat and need further help, post back.

Edit.

Here's a sketch for you.

 

[aubrey4444]

First of all you cannot just swap the wires over 'number for number' because they are different products from different manufacturers and do not correspond. Were there not instructions
with the Heatlink explaining what each terminal does? Like this.

View attachment 120189

Anyway, it's good that you took a photo of the original wiring. The wires at your original programmer were as follows:

N= 'Neutral' Blue & Black wires
L = 'Live' Brown and Red wires
1 'Hot Water Satisfied' = White wire
3 'Hot Water Call for Heat' - Black wire
4 'Heating Call for heat' = Brown wire

The good news is that the N and L will be correct as you have moved them, so if you look at the diagram for the Heatlink you will see which terminals correspond to the others. In fact johnmdc has already told you.


You also need to link the L terminal to terminals 2 and 5, again as already advised.

The main difficulty comes if you have an existing wired room thermostat, which will need decommissioning, so that the Nest can take full control of the heating. Unfortunately it can't just be disconnected otherwise the heating won't work. If you do have an existing room thermostat and need further help, post back.

Ok again you say You also need to link the L terminal to terminals 2 and 5...

What do you mean by this ?

 

[aptsys]

link

verb

UK /lɪŋk/
connection between two or more people, things, or ideas

 

[stem]

Ok again you say You also need to link the L terminal to terminals 2 and 5...

What do you mean by this ?

I mean link the L terminal to terminals 2 and 5, see below.

 

[aubrey4444]

First of all you cannot just swap the wires over 'number for number' because they are different products from different manufacturers and do not correspond. Were there not instructions
with the Heatlink explaining what each terminal does? Like this.

View attachment 120189

Anyway, it's good that you took a photo of the original wiring. The wires at your original programmer were as follows:

N= 'Neutral' Blue & Black wires
L = 'Live' Brown and Red wires
1 'Hot Water Satisfied' = White wire
3 'Hot Water Call for Heat' - Black wire
4 'Heating Call for heat' = Brown wire

The good news is that the N and L will be correct as you have moved them, so if you look at the diagram for the Heatlink you will see which terminals correspond to the others. In fact johnmdc has already told you.


You also need to link the L terminal to terminals 2 and 5, again as already advised.

The main difficulty comes if you have an existing wired room thermostat, which will need decommissioning, so that the Nest can take full control of the heating. Unfortunately it can't just be disconnected otherwise the heating won't work. If you do have an existing room thermostat and need further help, post back.

Edit.

Here's a sketch for you.

View attachment 120190

So from the sketch it looks like I have to use another wire to go from L Ter to Terminals 2/5 is this correct?

Thanks for the help

 

[stem]

Yes that's the idea.

Were there no instructions with your Heatlink? Page 25 shows L, 2, and 5 linked together.

 

[aubrey4444]

Yes that's the idea.

Were there no instructions with your Heatlink?

Excellent! I will give it ago when back from work and post back when it's done

Oh just to let you know it's a Y plan set up I have don't know if that makes a difference

Again massive thanks for the help

 

[stem]

And the existing room thermostat? is there one?

 

[aubrey4444]

And the existing room thermostat? is there one?

Yes there is but it's wireless and runs off battery not connected by any wires!

 

[stem]

The thermostat itself maybe wireless, but there will be a receiver somewhere that it communicates with that has the necessary wires connected to it.

It maybe that your existing Honeywell programmer / timer had the receiver inbuilt, if so that's fine as you are replacing it. However, I don't think this is likely. So, if you can tell us the make and model of the existing wireless thermostat we can advise further.

Oh just to let you know it's a Y plan set up I have don't know if that makes a difference

We knew that already as we can tell from the wiring. In fact, if you look at the page of the manual I posted you earlier you will see that it's headed Y Plan.