Heat pumps: have a cosy home without warming the planet

Home owners can get help from government schemes but do they really cut costs?

When Graham Davidson and his wife, Pauline, retired to a bungalow in Norfolk three years ago they ripped out the old boiler and replaced it with an air source heat pump at a cost of 10,000. But this pricey replacement has turned into a moneyspinner for the Davidsons - and millions of British households are likely to follow suit in what is expected to be a revolution in home heating.

Davidson, 68, who used to work in the car electronics business, says it was financial gain rather than saving the planet that was at the forefront of his decision. But dumping the gas boiler has probably cut his household carbon emissions by more than half.