So I am buying a house, and I know a little about bosch geothermal heat pumps. So here goes my silly question. There is a heat pump on the third floor of this house, but its a water to water source. Here is the part im not really understanding, why in the world is the water in connected to the hot water house supply. I always thought that most house heat pumps use refrigerant. and water to water was mainly for pump and dump and closed loop geo thermal systems. Sorry this is not my field, I am a PV installer and can help with electrical problems mostly, which this isnt lol.