What if the car heater is not hot?

The treatment method of warm air in the car is: 1, and check whether the filter is dirty or blocked; 2. Check whether the hot and cold air control flap cable in the heater box falls off, whether the heater impeller is damaged, whether the flap falls off, etc. The reasons why the heating in the car is not hot are: 1, the thermostat is often turned on or turned on too early, which makes the cooling system circulate too early and the external temperature is very low; 2. The water pump impeller is damaged or lost, so that the flow through the warm air small water tank is not enough, and the heat does not come up; 3. There is air resistance in the engine cooling system, which leads to poor circulation of the cooling system and failure of the warm air; 4. The filter screen is dirty and blocked, which leads to insufficient air volume or poor distribution of hot and cold air, so that the heat of the warm air small water tank cannot be radiated.