Salus to Nest heatlink Install

13 Nov 2019
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United Kingdom

I'm installing a Nest thermostat (3rd Gen) and just wanted to check with the experts that I had understood the wiring of the Heat Link correctly. It's a combi boiler (Valiant ecoTec plus 845). I will just be controlling the heating not water.

I think it should be:

Grey wire in Salus NO = Nest Heatlink (3) Heating call for heat

Black wire in Salus COM = Nest Heatlink (2) Heating common

Brown Wire in Salus L = Nest Heatlink (L)

Blue Wire in Salus N = Nest Heatlink (N)

I've attached an image of the existing setup.

Thanks in advance!

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Both the NO and COM look Grey to me but yes that is correct, doesnt matter which way round these two wires are connected to 2&3 on the nest, do not use any links
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The text is all good macster, except for the Nest Heat link Diagram you posted.

The one you want is this.


You should not link L and 2 as is shown in the diagram you posted. But from your comments I think you know this and just posted the wrong diagram in error. [with this diagram A (2) is COM and B (3) is NO]
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Hi there, decided not to create a new thread. I’m trying to do a similar thing, but my SALUS unit is wired currently like this. Could you please help as to what goes where?

You should have started a new post really & not hijacked someone else's. It often causes confusion later.

As you only mention a room thermostat, and not any other components such as a stored hot water system (hot water cylinder) or a timeswitch / programmer, I assume that they don't exist and the Salus is the only control fitted to your heating system. If so, you can proceed as follows:

Black wire in Salus N = Nest N
Red wire in Salus L = Nest L
Red wire in Salus NO = Nest 3 Heating call for heat

Add a wire link between Nest 2 and Nest L

If there are any other controls fitted to your system, or you have a hot water cylinder, the information given may be different.
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