Indoor hydraulic unit for RTC heat pumps designed for connecting inverter heat pumps directly to the heating system. The control display allows the setting of the basic system parameters and can be moved to the living part of the house where it can also act as a room temperature sensor. It contains a smart controller, electric heating elements of 2-12 kW output range, a circulation pump, a three-way zone valve for the hot water storage tank, the necessary circuit breakers and contactors.