Driver side air con blowing hot air

[chneo1982]

Anyone experienced this before in a W212?

Sent in to CNC twice already.

First time tell me the stepper motor out of steps.

Second time tell me must upgrade software.

Any outside workshops that can solve this?

[Toh Tommi]

I experience this in my w221. Especially when I first start the car. Then the air come out is hot one...I tried waiting for a while hopping it will turn cold... But it doesn't.... Until I press temperature down then suddenly become cold air.... Is yours lidat??

[chneo1982]

I experience this in my w221. Especially when I first start the car. Then the air come out is hot one...I tried waiting for a while hopping it will turn cold... But it doesn't.... Until I press temperature down then suddenly become cold air.... Is yours lidat??

No. Mine is passenger side cold, driver side hot.

[Machi]

try topping up the air con gas...

Chances are that the coils is leaking

[chneo1982]

try topping up the air con gas...

Chances are that the coils is leaking

Can't be cos passenger side is still very cold.

This afternoon driver side air con decided to come back again. It's cold now.

What is happening!?

[Machi]

It could be a couple of things. First thing you need to do is run the climate control diagnostics (any workshop that is reputable for Mercedes).

It is advisable to go top up the air con gas...

This often happens when the refrigerant is low. Maybe you have a leak on the A/C system.

OR Get your heater solonoid valves checked, a common fault they often stick open or closed, if you wish to check them your self they can be located behind the false bulkhead. Run the engine to normal engine running temperature with the heater in the cold position, the valves should be closed so the pipes leading to the heater matrix should be cold /colder than the hoses coming from the engine.

[chneo1982]

Where is this false bulkhead? Got any pics to show? U mean I can rectify this myself?

[Machi]

Better to get qualify technician to do it...