Arthur wrote:
How does a 400W single heat setting heater run at 1p an hour?

A very quick look at British Gas's website shows that their typical 'night'
rate (on Economy 7) is around 2.5p/kwh. A 400w heater will therefore cost
1p/hour to run at that rate.

Of course, most people will want to use this kind of heating during the day
or evening, when it's likely to be closer to 10-15p/kwh, but their statement
is technically correct (they do mention 'from 1p/hour').

John.