You can use old car a/c temperature control switch. It designed for high
current and 12 V, all you need to do is adjust the temperature setting on
the switch. There is a small screw for adjustment. By default it is set for
74-76 F to turn the AC compressor on and off.


"Neil" wrote in message
...
Can anyone recommend a thermostat that does not require a power supply and
can switch a 12v heater?