On Wed, 14 Oct 2009 13:27:08 +0100, Ed wrote:

So perhaps the max/fan output setting might be best to stir the heat
about and ensure that the whole of the room get up to the temperature as
set by the thermostat

It will bring the room up faster and give more of an "instant warmth"
effect. Once up to temperature it shouldn't make any difference which
setting you use assuming that the lower power ones have enough power
to replace the heat faster than it is being lost.

Whats the difference in cost between:

3kW for 20 mins
or
1kW for 60 mins

Nothing, both are 1kWhr of energy consumed. The latter may give
better comfort as the room temperature will vary less. So on that
basis I'd use the lowest setting consistent with maintaining the room
temperature.

--
Cheers
Dave.