Why is there no warm air in BMW 5 Series?

1, the refrigeration system is short of cooling liquid, so the car air conditioning warm air comes from it, and the principle is different from that of domestic air conditioning heating. Automobile warm air circulation is to connect a pipeline in parallel in the small circulation pipeline of engine coolant, which is connected with a warm air water tank, and the blower blows the warm air water tank to generate warm air, which is how the air conditioning warm air comes from. The lack of coolant in the cooling system is the most common and easily solved fault phenomenon that causes the warm air not to be hot.

2, warm water valve failure, warm water valve is common in luxury brand models, it is actually an electronic control valve. The warm water valve is installed between the water inlet pipe of the warm water tank and the small circulating pipeline of the engine, and the opening of the valve is controlled by the air-conditioning computer, so as to control the flow rate of coolant entering the warm water tank and achieve the purpose of controlling the warm air temperature of the air conditioner more accurately.

Extended data:

1, heater box blocked. The structure of the heater box is actually a miniature version of the radiator of the engine water tank. 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.