What this box for with the red light?

Danielll

The thermostat stop working last night and the heating stopped working, this box has never been touched and always been on red however when we put in on green the heating sort of starts to work

PC7060

Hi Daniel, Where are you located? Can you send us a picture from a bit farther back that show the boiler (or furnace)?

kcopp

From the looks of this its in the UK.

PC7060

kcopp said:

From the looks of this its in the UK.

That's what I thought from the electrics.

MrScott

Can you get it (gently) off its mounting and take a picture of the back?  Seems like there might be labels back there.

JDHW

The box is a receiver for a wireless thermostat (probably honeywell). When it is working normally it show nothing or a green light when calling for heat. I red light means not connected to the the thermostat. Have you changed the batteries in the thermostat?

Regards
John W.

JimUK

I'm a home owner not a pro, but am in the UK.

Yes, that is the receiver ( aka"Relay Box" ) for a RF linked room thermostat.

The room stat and receiver combination are available under a few brand names.

I think the box to the left in the picture is the timer programmer ( time intervals, not different temperatures ) also seen with various brand names.

As suggested, the red light indicates a loss of communication from the room stat.
The Relay Box probably then operates in a "fail safe" mode; which might depend on options set when installing it.

The room stat will have some indication of problems, low battery, internal fault, loss of RF communications.
If it just needs fresh batteries then RF communications should resume ok, it should not need a re-binding procedure ( but ... ).

If the relay box behaves as mine does, then pressing the button on the box gives "a temporary overide" of the relay position.