Mind you, if you look closely on their website, it works with gas heating - which most of the houses here use. I personally have a Buderus ( although fully automated - but quite inflexible) and I'd really like to try it. 300 Euro doesn't seem to much, considering that it can do savings on the same level per year. EDIT: the central Munich is heated with the SWM's powerplants. But around Munich there is a huge amount of houses which just fit this device.