What's the best way to turn a heater on and off.

[Ian]

My wife is rather forgetfull and so I'm worried that she will leave the plinth heater (2.4kW) on for 24 hrs in the (Wickes) conservatory I just put up.

I would like it to switch on when someone enters and switch off after no movement is detected for, say, 15 minutes.

I don't think I can connect the heater directly to a PIR because it's an inductive load. I could use a contactor, I just got one from E-Bay but it's rather huge.

Could I use a room thermostat operated from a PIR?. I have one that says 16/250 on the inside contact but in the manual it says "open contact 10A-250v and close contact 3A-250v" Maybe it's sufficient for 2.4kW but it's possible someone may connect a 3kW in the future.

Any suggestions would be welcome as its getting cold in there now.

[Peter Andrews]

Use a Horstmann timer

this allows for the heater to be turned on for 1/2, 1 or 2 hours. I use them at our Guide Hall for the water heaters and wall heaters - makes sure that they are not left on for too long if somebody forgets to turn them off when leaving.

Peter