Domestic hot water heating often requires higher temperature water than space heating does. This is due to the fact that heat is being transferred to a 120F or greater sink rather than the 70F air in a space heat application. There are several ways to configure a domestic water heating system. The two most common are storage recharge and instantaneous. There is also the possibility of using the geothermal water directly as makeup to the domestic hot water heater if the water chemistry permits