I had never encountered one before. Quickly, it became apparent that the heat pump didn't work properly, but fortunately it was under guarantee and once it had been replaced it worked very well indeed. In fact, we went on to buy a second one for our loft extension. The other reason I'm interested in this topic is because I'm excited by the prospect of witnessing a historic change - a horses-to-cars type moment. Since the stone age, people have typically kept themselves warm by burning things - wood or coal on a fire, or oil or gas in a boiler. A society-wide shift to electric heat pumps would mark a transformation to a whole new way of creating heat in the home. This government wants Britons to embrace heat pumps (as did the last). But it's a shift that comes loaded with complicated questions in a country where electricity costs so much. Currently they're more expensive than a gas boiler to install, and can also end up more expensive to run.…