1, check the car body and air conditioning system with a computer to see if there is a fault code. Secondly, if there is a lot of antifreeze that is not hot and the air can't be discharged, you need to check the water pump and warm water valve to see if there is a problem. The water circulation is not good and the warm air tank is too dirty, which leads to poor heating effect.
It may be because the heating pipe is blocked. This can be judged by yourself. Open the engine compartment cover and touch the heater upper and lower water pipes with your hands. If the temperature difference between the upper and lower water pipes is large, it will be blocked. After blockage, the heated air will not get hot.