On Sunday, September 30, 2012 10:14:50 AM UTC+1, charles wrote:

but if you could variably control the output so that it was what the
room needed to maintain the temperature, it would probably be more comfortable
than the simple ON or OFF normally used.

I'm in the process of cobbling together a Honeywell DT90E stat with a remote controlled socket to provide wirefree control of a convector heater in a conservatory. The stat employs their 'Time Proportional & Integral' functionality so it'll be interesting to see how accurately it manages to hold a temperature. Unlike on my central heating I'll be setting the cycle time and min on/off period as short as possible.

Mathew