What is the reason why the BMW 5 Series heater is set to 28 degrees?

The reason why the BMW 5 Series warm air is adjusted to 28 degrees is not hot: the cooling system lacks coolant; Warm water valve failure; The warm air water tank is blocked, and the speed of coolant flowing through it slows down, the flow rate becomes smaller, and the heat is insufficient; Temperature controller failure, resulting in low water temperature for a long time. In winter, the car air conditioner heats, and the warm air comes from the heat generated when the engine works. When the cooling system of the engine radiates heat to the engine, the radiated heat is sent into the car through the fan to form warm air. Take BMW 5 Series 2022 as an example. Its body adopts a four-door five-seat car structure, with a top speed of 230km/h, an acceleration time of 8.6 seconds per 100 km and a fuel tank volume of 68l. The power system adopts a 2.0l turbocharged engine and an 8-speed automatic manual transmission. Million car purchase subsidy