Replacing ITSalus 500 with Nest Thermostat E

[nycvisa]

Hi - i want to replace my Salus IT 500 thermostat with the Nest E. Can someone help me understand how i need to replace the heat links? currently, there is a hearlink that is connected directly to the boiler (that is the Salus IT500 one). Can i just open that one/unscrew the wires there and screw them back in the Nest E thermostat heatlink? I plan on using the actual round dial as a standalone on a desk/table top hence i thought that just swapping the two heatlinks would do it.

Am i correct/would i have any issue with voltage? Also, it is a combi boiler, so heat only.

Would appreciate the help

Nycvi

 

[stem]

Also, it is a combi boiler, so heat only.

A 'Combi boiler' is not a 'Heat only boiler' they are different things.

1. A 'combi boiler' provides central heating, and also instantaneous hot water on demand when a tap is opened.
2. A 'heat only boiler' heats water that is then directed externally to either radiators or a hot water cylinder.

Assuming that you do have a combi boiler, there are basically two ways of connecting it to a Salus IT 500 as shown in the diagrams from the Salus manual below. Which applies to yours, or do you have something else?

We'll leave it at that for now, but if you do have a heat only boiler there are other variants to choose from.

 

[nycvisa]

Thanks for the response. It is a combi one, what i meant by saying “hear only” was that i would only need the Nest to be setup to control the heat/not the water.

So basically, do i need to completely disconnect the Salus heatlink and plug in the Nest heatlink in its place (i assume the case), or is there a way to connect the Nest’s own heatlink to the already connected Salus heatlink? Presuming the former, would i need to worry about voltage here?

Thanks in advance afain

 

[ianmcd]

what make and model of boiler do you have ? the nest E is only compatible with 24V switching and not 240V

 

[stem]

You need to replace the whole Salus with the Nest, their parts are not interchangeable, but voltage will still be important, so first you need to answer the question posed by @ianmcd

 

[nycvisa]

yep thanks. i need to go to the property and take a look/picture and will revert. thanks vm for the help so far

 

[stem]

There are also different versions of the Nest e. Some that mistakenly find their way over here, usually via overseas based websites are designed for 24v USA blown air and air conditioning systems. They look like this.

The UK version of the Nest e Thermostat receiver looks like this.

Which version do you have?

 

[Nabih]

I I have the same issue I bought the thermostat e and based on the website it should be compatible, however, my wireless sales connected like the picture B and when I followed the steps on the app to connect it it didn't work, is there a way to connect it?

 

[stem]

With the UK version of Nest e, for 230v combi control then:

The live supply currently going to the Salus, now goes to 'C' on the Nest e

The neutral to the Salus will not be required. Do not connect it to the Nest e. Isolate / insulate it and tuck it out of the way.

The wire in 'NO' of the Salus, now goes to 'NO' on the nest e

 

[Nabih]

this is the current setup, when I followed the app it told me to take the NO and COM from salus and connect them to Nest but when I did that there was no power to boiler
so if I connect them the way you explained it will not blow up the boiler? I'm more bothered about the boiler than the Nest to be honest lol

 

[ianmcd]

the nest E is different from other nest models in that the hub is battery powered, hence why @stem has told you to isolate the neutral, his information is correct on how to wire your new thermostat, you only need to use the wires in NO and Com

 

[Nabih]

by saying only using the wires in No and COM you mean NO and L?, I used the wires from NO and COM but there was no power, however there is a junction connecting COM and L on the existing Salus in my boiler. thanks for clarifying that
looking at the pictures I sent so the brown cable going to the L in the salus goes to the COM in heatlink and the Black cable that is coming from the boiler into NO in the salus goes to the NO on the heatlink

 

[stem]

You originally said that you have wiring as per Salus diagram B which is as follows: [The colours of the wires used may be different for your installation]

The same wires would go to the Nest e as follows:

From your photo you appear to have two blue wires in N, if so, they need to remain connected together, but still isolated from the Nest e, like this.

The external wires in separate terminals and not connected to the Salus remain connected as they are.

 

[Nabih]

that's absolutely brilliant thanks your a gen, if you have a look at my pictures, I have 2 brown wires from 2 separate cables I'm guessing one is from the mains and one coming from the boiler, one as you showed is going to the L terminal of the salus and the other is going in COM terminal of the Salus and the L and COM are joined, my question is what do I do with the other brown wire that's currently in the COM terminal?

 

[stem]

For future reference you should have really started your own thread. Tagging your question on to someone else's thread is known as hijacking and is against the forum rules. I mention it now, because the original post was about about a ITSalus 500, but from your photo's I see that your thermostat is actually a different model (Salus rt500rf) Fortunately the terminals are labelled the same but are in different places. Don't start a new thread now though because then you will have duplicate threads running on the same topic and that's also against the rules.

Unfortunately. I cannot see your photo's clearly enough to be absolutely sure what coloured wires go where. It appears to be:

NO = One brown wire
Com = Loop (end 1)
L = One brown wire & loop (end 2)
N = Two blue wires

Is this correct?