It will be hot when the car is refueled with warm air, but it will not be hot without refueling, and the temperature of the water tank will not rise.

The heater water tank is blocked. The structure of the warm air water tank is actually a miniature version of the radiator of the engine water tank, and there are many small cooling pipes in it, which are as easy to block as the radiator of the water tank. After the inside of the warm air water tank is blocked, the coolant flows slowly, the flow rate becomes smaller, and the heat is insufficient, so the air conditioner warm air is naturally not hot.

Extended data

The problem of air volume control mechanism;

1, the car's warm air uses a blower to blow the heat from the warm air small water tank into the cab. If the air volume is insufficient or the distribution of cold and hot air is not good, the heat of the small warm air tank will not be radiated, and the temperature of the warm air will not come up. At this point, first check whether the filter element is dirty or blocked, clean it, and replace it in time if necessary.

2. Check the operation of each gear of the blower to ensure that each gear has sufficient speed. If the knob is set to the warm air position, the air volume is large enough and the wind direction is normal, and the cold air is blown out, check whether the cable of the hot and cold air control flap in the warm air box falls off, whether the warm air impeller is damaged, whether the flap falls off, etc. After troubleshooting, the warm air will get hot.