Nest e Thermostat wiring help

[Bobrob]

I am trying to swop out a SalusRXRT500 wireless receiver for the nest e heat link, the salus has 4 wires connected marked NO Com L N the boiler is a combi, can anyone tell me which wires are connected and which are isolated. Thanks

 

[stem]

SalusRXRT500

I'v not heard of this model, but I suspect by the wiring connections you describe, that you mean a Salus RT500RF. If so, the Nest e, is battery operated, but the Salus is mains powered, so the 230V power supply for the Salus N and L will not be required by the Nest e and should be isolated / insulated and put safely out of the way.

Then the remaining wires are connected as follows:

Wire in Salus 'NO' = Nest e 'NO'
Wire in Salus 'COM' = Nest e 'C'

NOTE: You may find (depending upon how the Salus was originally installed) that the Salus 'L' and Salus 'COM' have a single wire connected to both terminals by the use of a wire link betwen them. In this case, loose the link and the single wire goes to the Nest e 'C'

If you are unsure of anything post back. A photo of the wires going to the Salus terminals would assist with any further questions.

 

[Bobrob]

Hi. Thanks for your reply, isuspected your answer was the way to go. What confused me about my existing setup was the fact that the receiver is wired with a 4 cable lead and the original installer has used the earth coloured cable to connect to the NO connector, he probably knew why he used that but confusing for anyone following later.

 

[stem]

When it comes to heating systems, green / yellow wires are often used as live wire, usually out of lazyness when an additional cable should really be installed.

It's not ideal, and it does cause confusion. As a minimum the wire should have a brown sleeve fitted over it.

 

[Bobrob]

Hi. Thanks again. Yes that was my thought as well, would have been better to sleeve it. Did try to post a picture of the receiver wiring but could not work out how. I am an old man so a bit behind with techy things.