What's wrong with the new Jetta warm air?

The new Jetta heater is not hot: 1. Lack of antifreeze; 2. The heater water tank is blocked and the circulation is not smooth. The solution to the lack of antifreeze is to replenish antifreeze in time. The solution to the blockage and poor circulation of the warm air tank is: it is necessary to clean the warm air tank to ensure the water circulation until it returns to normal. The manufacturer of Jetta is FAW-Volkswagen, which is a compact car with an engine of 1.4LL4. The air intake mode is naturally aspirated. The length, width and height of the car are 451mm, 174mm and 1469mm respectively, and the wheelbase is 264 mm. The body type is a four-door five-seater sedan, and the gearbox is manual in 5th gear.