Control failure of water valve of Mercedes-Benz 220 heater

The one-way water valve of the heater is broken. The control fault of Mercedes-Benz 220 heater water valve is that the one-way water valve of heater fan is broken. Because the water in the water tank contains chemical components such as antifreeze, it will corrode the one-way water valve to a certain extent after a long time. The one-way water valve is broken, and it will definitely leak. It can be replaced in the 4S shop, and the radiator in the water tank can be replaced at the same time, and the inside and outside of the water tank can be cleaned.