To provide a heating device for a motor vehicle that includes an electrical propulsion system and promotes efficient energy management.

A PTC based heating device for the motor vehicle with an electrical propulsion system uses a liquid medium as a heat transfer medium, has an electric PTC heating element 20 arranged in a heating circuit in order to heat the liquid medium, and is countersunk head, and further includes an auxiliary circuit which has a separate heat source 50 which can be alternatively incorporated into the heating circuit.