It has been almost a year since I bought the new Changan Ford Fiesta. Why was there hot air blowing when I turned on the air conditioner while driving yesterday?

The air vents of Carnival are designed so that the air flows into the evaporation box of the air conditioner and flows through the warm air water tank. There is no damper in the middle to control the cold and heat. The warm air water valve is used to cut off the heat source of the warm air water tank. It is possible that the heater water valve is faulty, causing hot water to continue to enter the heater water tank and hot air comes out. It is also possible that the circuit is faulty, giving an incorrect instruction to the heater water valve to open. Troubleshooting method: Because the air conditioning control system of the Carnival is relatively complex, you must go to a professional repair station for maintenance and diagnosis.