MoesGo Thermostat Install

[DarrCon]

Hello.
I’m trying to replace a standard dial thermostat with a MoesGo 002-GC WiFi Smart thermostat.
Behind the thermostat there are two full live/neutral/earth wires. One is not used and only has 115-120v. The other wire is used for on/off for the boiler.
I have had a professional electrician look at it but he was stumped. If anyone can offer any advice I would be extremely grateful. Thank you.

 

[Deleted member 267285]

If the full live and neutrals (as you’re calling them) are what you say and are permanent, and are 240vac on live and 0-15vac on Neutral then you could go:

Permanent live to L on Moes Go
Permanent neutral to N on Moes Go
1 on Honeywell to 1 on Moes Go
3 on Honeywell to 2 on Moes Go

If not, then you need to get a permanent live and permanent neutral to your Moes Go.

 

[DarrCon]

Thanks Chris. the permanent live is only 115-120v so isn’t giving enough juice. I heard I need to link to earth to get 240v but I’m really not sure.

 

[Deleted member 267285]

I wouldn’t be linking line/live to earth. I don’t know why you’re only getting 120vac, something sounds amiss. Might be worth getting a heating engineers in to test the whole wiring, unless it’s something you feel you can do? If a professional electrician can’t sort it though?

 

[stem]

What you have is a very bad installation. It's wrong on several levels from just what can be seen. If you look inside the lid of the thermostat you will see how it should be wired.

1. Terminal 1 of the thermostat should be a live supply connected to it.

But yours has a black wire in it ......I would have thought it unlikely to be connected to a live supply at the other end... Maybe..., maybe not.

2. To work properly, the thermostat should have a neutral connection to terminal 2

Yours doesn't have any connection made to terminal 2. If one of the mystery wires was a neutral I would expect to see it connect to terminal 2.

3. The cables pass through a rather badly fitted metal backplate and I can't see any protective grommet fitted.

So what lurks elsewhere who knows. You can't proceed safely until you can't identify exactly what is on the other end of each of the wires.

On the plus side, there does appear to be an earth connection made to the metal backplate in the top left hand corner and it actually has green / yellow sleeve on.

 

[Deleted member 267285]

@DarrCon this user @stem - is a very professional electrician

 

[ericmark]

The MoesGo 002-GC WiFi Smart thermostat is only £35 so very popular, but it needs line in, line out and neutral, plus you must have an earth even if not used, the only WiFi Smart thermostat that does not need a neutral that I know of is the Nest e at £180, which is battery powered.

Even the old mechanical thermostats should have had a neutral in most cases, however when the thermostat is only used to stop the boiler cycling in the summer the high hysteresis caused by no neutral could actually be a benefit so often left out.

You can get loads of battery operated thermostats which don't need a neutral, even programmable ones, but not WiFi Smart thermostats other than the Nest e.

So then you look at wireless thermostats, but under £100 often they will not fail safe, so it is either rewire, or much more expensive thermostat.

 

[DarrCon]

Thanks everyone.
It seemed like it was going to be difficult so thanks for confirming that. Time to look for another option.