1, insufficient coolant, reason-due to the damage of engine water circulation system parts and joint leakage or cylinder gasket, the coolant is insufficient, so that only a small amount of coolant circulates in the warm air pipeline or does not circulate at all, resulting in the warm air is not hot. Solution-just add coolant to ensure the normal water circulation system of the engine. If there are other problems, please solve them first, and then add coolant to the normal level.
2. Thermostat: The reason is that the thermostat was removed and not installed because of the high water temperature during the previous maintenance, or it was damaged in the normally open position, which kept the water circulation of the engine in a state of large circulation. Because of the low external temperature and good heat dissipation, it is difficult to raise the water temperature of the engine, so the warm air is not hot. Solution-Add or replace a new thermostat.
3. Warm air water tank and heat exchanger. Reason-Part A automatic transmission models are equipped with a heat exchanger on the gearbox, and the engine coolant enters the warm air water tank through the heat exchanger. If the heat exchanger is blocked, the warm air is not hot. B There are also some models of water heaters with air outlets near the water tank, which will lead to the water heater not being hot if the air is not completely exhausted. Solution-If there is an exhaust port, exhaust the air first. If you can't touch the two heating pipes by hand and the temperature difference is great, use a water gun or air gun to directly connect the heating tank or heat exchanger.
4. Warm air control mechanism, because of the cold and hot servo motor of air conditioning panel. The heater water valve and other components are damaged or the heater system circuit is faulty, which leads to the heater not being used normally. Solution-find out the reasons and deal with the specific problems.