Why two stats?

[uselessFCUK]

Hi y'all

Potterton Homewarmer gas BBU: gravity DHW / pumped CH

Switchmaster SM400 Programmer

We have two Satchwell room stats; a 'TL 25' is in the living room where the BBU and Potterton Homewarmer Legend fire is and no radiator.

The other is a 'TL 25T' and is in the hall where there is a rad.

I've tried to locate any info on these to no avail.

Why is there two and how are they meant to be set-up?

What's the purpose of the one in the room with no rad? Is one stat set as 'master'?


Thanks in advance. UF

 

[twgas]

are they both connected?

 

[uselessFCUK]

Yep

 

[JohnD]

the 'TL 25T' must surely be so that you can set diff temps for diff times, e.g. a night-time and a day-time temp. And the "T" suffix probably means it is to be used with a timer.

 

[twgas]

T may also mean its got a thermometer fixed to it

 

[JohnD]

ah...

is the upper wheel a thermometer? didn't think of that.

 

[twgas]

I believe so.

 

[D_Hailsham]

are they both connected?

How are they connected? You will need to find the other end of the cables from each thermostat. They could be in parallel - both thermostats connected to the same pair of terminals, or in series like this: terminal - stat 1 -stat 2 - terminal.

Is there any sign that there ever was a rad in the living room? If there isn't, and the only source of heat is the gas fire, a thermostat will do nothing in that room.

My guess is that the stat in the living room is the original one but, with no rad there it is virtually useless so the one in the hall was added later to provide better control temperature in the rest of the house.

 

[uselessFCUK]

Is there any sign that there ever was a rad in the living room? If there isn't, and the only source of heat is the gas fire, a thermostat will do nothing in that room.

No sign of any rad. Exactly the same setup in my nan's house on the same estate, and she's been there since day one.

The stat in the hall, TL 25T, has the top dial attached to a coiled tape... perhaps a thermometer as suggested.

These two stats are three steps apart through a doorway and the hall stat is about 6ft from the hall rad.

We've only just moved in so I'll have to fiddle with the heating on.

Thanks so far.