A class climate control

[patrickl.k.so]

Hi

I just got an yr98 A class 160, happy become a MB owner.

Did I need to switch on both "EC" & "circulation" buttons for cool air
supply?

Actually, when I switch on both buttons, cool air comes. But around 5
minutes later, the "circulation" button switch off automatically and no more
cool air.

As a result, I need to switch off and switch on the "EC" button in order to
resume the cool air supply.

Is it a normal case for this model, or something I needed to check?
Or, I need to switch off the "EC" button (red light off) in order to get cool air...

Thanks.

[pigtail]

Circulation: cooling, no outside air coming in.

EC: no cooling, no dehumidification, outside air in.

Refer Owner's Manual page 106