Replacing old 230V thermostat

Rothman · 7 Oct 2015

Hi,

I'm looking at replacing my old thermostat, which is powered at 230V directly into it, and I have another wire (I imagine the switch?) running back to the boiler.

I bought a nest last week thinking I'd be able to do a complete like for like replacement, however that doesn't look to be the case as the thermostat unit for nest is purely 12V and the link which needs 230V comes off the boiler. Ideally I wanted something to replace my old thermostat in its current location as I have recently redecorated and left the space and wiring available so rewiring is out of the question, and really, so is putting the nest in another location just off a plug socket.

Am I correct in saying British Gas's hive system is exactly the same set-up? I can't really find a lot of information on it in terms of replacing a thermostat that is 230V powered.

I'd like to move into the smart era, however are my options limited as all the thermostats in this range are NOT 230V?

Again, I must stipulate, rewiring is out of the question.

Thanks.

Dan Robinson · 7 Oct 2015

The Nest can be used, but I suggest you get a professional to do it.

Rothman · 7 Oct 2015

Oh really? Their compatibility check isn't great on the site; I filled out the wires I had and it said "sorry, not compatible" after I checked. As long as it can be done without rewiring OR relocating the nest, I'll be happy. But as I say, my current thermostat is powered directly and I've somehow got to switch that with a 12V unit!

Agile · 7 Oct 2015

As Dan says, your easiest option is to get a Nest registered installer to sort it out for you.

We don't encourage DIY 230v wiring and particularly not when an expensive item like a Nest is involved.

Have you bought/considered a Nest smoke alarm?

Tony Glazier

ollski · 7 Oct 2015

Dont know about the nest but you could wire the hive receiver into the boiler and leave it on top if you like and then put the programmer over the old stat position.

ollski · 7 Oct 2015

Can we not give gas or electric advice now?, are we still alright with water until someone floods their house?

Rothman · 7 Oct 2015

I'm perfectly comfortable with 230V wiring, I'm not going to go into what I can do as that's not up for debate, but I can be considered competent, I'm just not overly familiar with heating systems.

That's not what I'm getting at; I'm asking if there are other options for a smart system where my current one is wired directly at 230V and I have no option for rewiring.

Dan Robinson · 7 Oct 2015

Rothman said:
I'm perfectly comfortable with 230V wiring, I'm not going to go into what I can do as that's not up for debate, but I can be considered competent, I'm just not overly familiar with heating systems.

That's not what I'm getting at; I'm asking if there are other options for a smart system where my current one is wired directly at 230V and I have no option for rewiring.

Without meaning to cause offence.... I beg to differ on the matter of competence on the grounds of the question you've asked after seeing the instructions with the Nest.

Agile · 7 Oct 2015

Rothman, as Dan has said we assess poster's capabilities according to what they have posted.

I totally agree with Dan that you do NOT seem to have an appropriate understanding of wiring to be able to safely connect up a Nest. If you did then you would not have been asking about it here.

When there are installers all over the country who will do it for you at a reasonable price I don't see why you don't call one.

Tony

Rothman · 8 Oct 2015

Don't worry, problem solved. I had my heating engineer friend round last night, he talked me through the heating system. I understand it perfectly after a trace-through and found a workaround for the nest location in keeping it where the old thermostat is.

I'll reiterate, I AM perfectly capable of doing the wiring, but as I had no previous understanding of the heating system of a house as opposed to the rest of the electrical system, it was a grey area I required more info on so I could capitalise on the existing wiring I had. I now have that knowledge, the rest is child's play. What I was also more in the dark of was what the nest would require in terms of power, and I actually discovered that it can hold a fair charge once you unplug it from the mains dock.

Thanks all for your help.

Agile · 8 Oct 2015

It will only run for about 20 min after being disconnected from the 5v power supply.

Even less if its doing a lot of things during that time.

Of course its not difficult to construct a battery powered portable source with a 2-3 day capacity for anyone who wanted to use it portably.

Tony

Rothman · 8 Oct 2015

Ah so it's not exactly portable? Ok good, that's useful information! I've ordered a hive unit to compare the 2 before I consider which one to return. The hive looks good in that it controls hot water as well, and it's portable because it's battery operated.

I did have an idea about how I could've wall mounted it and kept a constant supply on it, but it'd look odd.

Dan Robinson · 8 Oct 2015

Why would it be portable?

Dean744PiN5 · 8 Oct 2015

How are you getting power to the nest, just out of curiosity?

bernardgreen · 9 Oct 2015

There is a Cuckoo in the Nest

EDIT the cucckoo's post has been removed.

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Replacing old 230V thermostat

Dean744PiN5

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