AIR CONDITIONER FOR VEHICLE

An air conditioner for a vehicle includes a heater core, a water pump, a pump motor, and a control system. The heater core is coupled to an engine cooling pipe. The water pump circulates a coolant inside the cooling pipe. The control system includes a processor and a memory communicably coupled to each other. The control system controls the pump motor in accordance with a heater core temperature. A first threshold and a third threshold lower than the first threshold are set in the control system. The control system operates the pump motor when the heater core temperature decreases to the first threshold after the engine is stopped and starts the engine when, after the temperature of the heater core decreases to the first threshold, the temperature of the heater core becomes equal to or lower than the third threshold while the pump motor is being operated.