Operating method for vehicle auxiliary heater involves periodically mixing water from second circuit into first circuit for short periods to determine water temp. in second circuit

摘要

The method involves operating a vehicle auxiliary heater (1) together with a heat exchanger (2) in a first water circuit (A) excluding the vehicle engine (4) or a second water circuit (B) including the engine with the aid of a valve arrangement (3) determining the water circuits. The valve opening state for mixing the water circuits is determined according to the water temp. in the second circuit. Water is periodically mixed from the second circuit into the first circuit for short periods to determine the temp. of the water in the second circuit according to a predefined mixing ratio.