MB500

Having a rather strange AC problem on my W211 and hoping that someone could help. When I turn AC on, I get plenty of cold air through the front vents, however, there is hot air coming from the rear vents. No matter what temperature I set on the rear control unit, the air is still very hot, as if the heater is set on its very warmest setting.

Can anyone provide any clues? Do you think that the rear control unit maybe faulty?

Thank you in advance!

konigstiger

Common problem, the heat exchanger valve needs to be replaced.

https://mbworld.org/forums/e-class-w211/215525-my-heater-will-not-blow-hot-air.html

DIY https://mbworld.org/forums/e-class-w211/216187-plastic-trim-bottom-windshield.html