My offer on a modern 2 bed house has just been accepted and I decided to research the heating system at the property. Now I am really worried as it is a Nibe exhaust air heat pump system which is supposed to be eco-friendly but has featured on various tv shows, with many people complaining about the sky high bills. Has any one had one of these systems? Are the always very expensive, ie. £10 per day to run in winter? If this is the case I will walk away from the property.