Hello! The water pipe of the heater tank must be closed when the car is turning on the air conditioner. For ordinary cars, in the cab, just turn the lever on the air conditioning panel to the blue position. If your car's heater switch is in the engine compartment, the heater water pipe is relatively thin, with a diameter of about two centimeters. You can first look for heating pipes. Are you looking at where the switch is? As for the twisting method of the heater switch, there are only two directions, one is off and the other is on. If you can't find it, it is recommended to go to the auto repair shop and ask the maintenance personnel to shut it down. Hope it helps. Car questions, ask the car guru. Professional technicians from 4S stores can solve the problem in 10 minutes.