Help installing WiFi thermostat.

[Hookie66]

Hi

I have a Myson thermostat and I want to replace it with a Wi-Fi switch / thermostat to simply turn the heating on and off when I’m on the way home. it doesn’t need to change the temperature.

The myson is battery operated but I’m trying to work out the wiring. (There’s also two Myson thermostat‘s in the property. One in the lounge and the other in the master bedroom)

The first picture is the wiring with the front off:
The second is the wiring behind the unit.

There’s 4 cables
Am I correct the brown and black are for the switch ?
The yellow/green is earth. (Which isn’t connected)
What is the grey? Is it some kind of power?

If I was to order thesr or something like these:

https://amzn.eu/d/eC3MQMb

https://amzn.eu/d/4ivI1Y0

would it work and how would i wire it up with this set up.

Thanks for the help.

 

[Deleted member 267285]

Grey could be neutral. One of the Amazon ones linked is for electric under floor heating, but can be changed. You could use a battery type if available or if the grey is neutral, then one of those. Have a look at Esi or EPH.

 

[Hookie66]

I asked someone else if it mattered that it said underfloor and they said it didn’t matter as it’s effectively a on / off switch.
Is that true?

 

[Deleted member 267285]

I asked someone else if it mattered that it said underfloor and they said it didn’t matter as it’s effectively a one off switch.
Is that true?

I suppose so

 

[Hookie66]

I can’t work this out…
The black and brown are for the switch and I’ve tried the grey in all the connectors am I missing something ?

 

[Deleted member 267285]

Try brown in L, grey in N and black in NO

 

[Hookie66]

Brilliant thanks for the help.