Reversible air/water heat pump Inverter for air conditioning systems with cold water production for cooling rooms and hot water for heating and/or domestic hot water services, suitable for connection with small or medium users. The unit is equipped with scroll compressor, axial flow fan, and plate type exchanger. The Plug&Play unit can be combined with low-temperature emission systems such as underfloor heating or fan coils. To facilitate the final installation, versions with the main hydraulic components are also available as standard.