Abstract: An auxiliary heating system for an internal combustion engine powered vehicle having a coolant system in which the conventional engine coolant pump circulates heated coolant from the engine to a heater radiator for transferring heat from the coolant to the vehicle passenger compartment includes a thermostatically controlled electric heating element and an electric pump located in a branch conduit receiving coolant from the heater radiator. The heating element and electric pump are selectively energizable by the vehicle operator to heat and circulate the engine coolant through a check valve and then through selectively actuated electrically controlled valves which direct it through the heater radiator, the engine or both when the engine is not running. The check valve isolates the heating element and electric pump from normal engine coolant circulation flow when the engine is running. In another embodiment an electrically controlled valve replaces the check valve for the same purpose.