New Thermostat Wiring

[schapmande13]

Hi,

I am replacing an old Potterton PRT100ST room thermostat with a new SALUS RT300 DIGITAL THERMOSTAT.

Is anyone able to confirm the wiring arrangement. I believe the new thermostat will not require all three wires from the old one (no neutral??)

OLD
N - Neutral
H - Heating Demand
TL - Thermostat Live

NEW
SL - Switched Live
L - Mains Live
And there is an earth parking terminal if required

Any confirmation on how this should be connected would be much appreciated!

 

[Jackrae]

It is powered by a pair of AA batteries, so no neutral is required.
The L and SL are the "output" terminals from the relay and are referred to as "volt-free" in that the thermostat does not apply any voltage to them.

You will need to terminate your neutral wire in a small insulated terminal block. Ideally the other end of the neutral cable should also be disconnected and similarly isolated

 

[schapmande13]

So of the H and TL on the old thermostat which is connected to SL on the new thermostat and which is connected to L?

 

[Jackrae]

It doesn't really matter as it's a set of "dumb" contacts but for correctness TL = L and H = SL

 

[schapmande13]

Many thanks - very helpful