Heat pumps for homes aren't expensive to operate. They are cheaper to "operate" than resistance heaters. I doubt they're a nightmare to fix - I have actually had to get mine "fixed" once. It was still fairly new, and it turned out there was a leak in the tube so the coolant gradually (over the last year) got out. The company came and fixed that easily enough. Since then (January 2011) the heat pump has been running 24/7 with no issues whatsoever. In fact you're not supposed to turn them off at all, the moving parts are supposed to keep moving. So, if I'm away for some weeks I simply set the temperature to the recommended "idle" temperature of 17C, which in practice means it's not really doing any work, but it's not off either.