Thermostat

[fire]

a thermosatat is supposed to work as a switch and open and close as the temparature changes, so why does it need a neutral?

can anyone help.

 

[Marvo]

If you connect a live and a neutral across the contact of a thermostat then stand well back when you switch on because it's going to blow it to pieces.

Just because a wire is black it doesn't necessarily mean it's a neutral. Someone could have used the black wire of the cable as a switched live but they ought to have sleeved or taped it as a different colour to indicate this.

 

[robd]

makes it more efficient I believe

 

[telectrix]

think he means some of the newer stats. which are electronic and need a supply rather than just the old bimetal switch, which is just L and S/L

 

[robd]

And more accurate if it's one with a bi-metalic strip

 

[fire]

the thermostat that i bougth from screwfix has the manufactures instruction in it and says that the neutral must be connected.

 

[robd]

Go back and get one that doesn't...i.e. not one with a bi-metallic strip in

 

[Marvo]

think he means some of the newer stats. which are electronic and need a supply rather than just the old bimetal switch, which is just L and S/L

Thanks for clarifying, we call those things energy regulators or simmerstats in this neck of the woods.

 

[Geordie Spark]

The neutral is to work a small heating element inside the thermostat. The heater makes the thermostat more sensitive to temperature changes in the ambient air, thus making for more accurate temperature control of the room.

Some of these 3 wire thermostats will work without the neutral connected, but not quite so fast or accurately.