What is the reason why the old Citroen Elysee heater is not hot? When the engine heats up to the normal working temperature, the temperature control switch is set to the warm air position, and the war

What is the reason why the old Citroen Elysee heater is not hot? When the engine heats up to the normal working temperature, the temperature control switch is set to the warm air position, and the warm air switch is turned on for heating. This is caused by the poor water circulation of the warm air tank, because the car is several years old. Usually, the scale is adsorbed on the small water tank, which leads to the blockage of the small pipes in the small water tank. The solution is to disassemble the inlet and outlet pipes of the small water tank and blow air into the small water tank with an air pump to blow out the dirty things inside. Just stick the inlet pipe and outlet pipe together.