[Sephiroth]

Originally Posted by Mad Max

The heat pumps use refrigerant, an air source heat pump costs more than a new gas or oil-fired central heating system. The typical air source heat pump cost ranges from £4,000-8,000, depending on the pump brand and its heat output.

Homes would currently spend p.a. between £1,000 and £2,500 (or more) on gas for heating/cooking. Apart from unemployment at British Gas, it seems to me that the £8,000 heat pump cost is an easily mortgageable item.