The sophisticated HabiStat Dimming Thermostat is designed specifically for controlling light bulbs. 
The Dimming Thermostat is one of the most accurate methods of temperature control and whilst it is perfect for controlling light bulbs, it can be used on almost any heaters. 
Unlike other HabiStat Thermostats, it does require a minimum load of 40 watts, but has a maximum capacity of 600 watts at 230 volts. 
We only recommend this thermostat for use with incandescent light bulbs. It uses the latest technology and operates in a manner similar to the Pulse Proportional Thermostat. 
Instead of pulses of power being supplied to the heater, it is supplied with a continuous variable supply of power or voltage. In principle this has a similar effect to light dimmers or rheostats in your home.