Trying to set up thermostat

[Scottishmammy]

THIS IS FOR ELECTRICAL NEWS ONLY

 

[littlespark]

THIS IS FOR ELECTRICAL NEWS ONLY

Well this is a strange one.

As with all questions like this, could you post a photograph of:

Any existing connections to present thermostat....

Wiring diagram of new thermostat.

 

[MJPD29]

Impossible to answer without more info

 

[brianmoooore]

I take it this is replacing a existing room stat?
It's fairly certain that brown is 'live in' and green/yellow is earth, and probable that grey is the 'switched live out' and black is neutral, but it's quite possible that these two are the other way around.
There should be small pieces of coloured sleeving on these latter two, identifying which is which.
The neutral would have been for a 'night setback' function on the old stat.

 

[littlespark]

I take it this is replacing a existing room stat?
It's fairly certain that brown is 'live in' and green/yellow is earth, and probable that grey is the 'switched live out' and black is neutral, but it's quite possible that these two are the other way around.
There should be small pieces of coloured sleeving on these latter two, identifying which is which.
The neutral would have been for a 'night setback' function on the old stat.

Whereas others will use grey as neutral and black as a switched live.
You can’t afford to get these mixed up!

 

[brianmoooore]

Whereas others will use grey as neutral and black as a switched live.

Which is what I meant to write as the first option. This is the 'correct' answer.
Shows how easy it is to get wrong, especially if you post on here late at night.