In this case, most of the reasons are that the water tank or water pipe is aging, resulting in insufficient antifreeze in the water tank.
How to judge and solve? Observe whether the water temperature is alarming or whether the water thermometer is high. The solution is to add antifreeze, and some cars must be deflated.
Second, the water temperature is normal and the warm air is not hot.
1, this problem should first consider whether the temperature control system (automatic air conditioner) and manual air conditioner have fallen off or have problems.
2. You can open the hood and feel whether the two water pipes (only two water pipes leading to the cab) entering and leaving the heater box are hot. If one is hot and the other is not, it is necessary to consider whether the warm air tank is blocked.
Third, the water temperature is normal. As soon as the heating is turned on, it will turn into a cool breeze.
First turn on the range hood and touch two water pipes. If the water pipe is hot, there is only one way to say that the warm air tank is blocked, but it can still circulate water normally, which only affects the heat of the outlet air. This situation is that the water pipe is hot, and the wind is hot first and then cold.