Abstract: In an arrangement of a vehicle auxiliary heater with an integrated regulating device in the region of the floor in the vehicle cab and a control unit remote from the auxiliary heater, e.g. in the region of the dashboard or on an inner wall of the vehicle, it is proposed that the control unit be operationally connected to the regulation device wirelessly via a bidirectional radio link in which use is made of an r.f. unit with a first r.f. module on the operating side with a transmission and reception section and a second r.f. module on the control device side with a second transmission and a reception section. This obviates the need for the complicated laying of prior art wired connections between the control unit and the regulating device of the auxiliary vehicle heater, making the heater particularly suitable for subsequent fitting in commercial vehicles.

Abstract: In the cooling system of a water-cooled engine for a vehicle, a heat exchanger is arranged for heating the interior of the vehicle using the heat extracted from the water which cools the engine. To provide rapid heating of the interior of the vehicle and preheating of the engine, a heating system is incorporated into the cooling system for selectively heating a portion of the cooling water to a desired temperature and then passing the heated water into the heat exchanger for heating the interior of the vehicle. After flowing through the heat exchanger, the heated water is passed through the water-cooled engine to preheat it.