Heating glitches s211

[Chattonmill]

Started out for Norfolk on Thursday got 15 miles and was getting rather cold as the heating had stopped working.
Eventaully decided to turn it off, then on again and it started working again.
Now it seems to be working a bit funny(Gets too hot and will only readjust when the temp is changed)
Also the cooler in the centre box now seems to be a heated box unit!
Are these related and is there a simple soloution?
Thanks
Max

 

[Diesel Benz]

You might check from your manual but I don't think the centre box should be cooled unless you have AC actively cooling the car. You can switch off the air flow if you don't want the box being warmed up.

The heating issue could be the heat exchanger shut-off valve. But it usually gets stuck wide open or closed, perhaps your car is approaching this state.

 

[Chattonmill]

How do you switch off the air flow? I prefer my chocolate to be solid rather than liquid!
Would the heat exchanger throw up a fault code, would get this done as the car still has MB warranty on it.

 

[Diesel Benz]

How do you switch off the air flow? I prefer my chocolate to be solid rather than liquid!
Would the heat exchanger throw up a fault code, would get this done as the car still has MB warranty on it.

At the front of the centre box there should be a lever allowing air flow to be closed.

I'm not sure if Star would see a stored fault code from the shut-off valve (workshop experts here would know) but at least it can be tested. Of course if it is intermediate only, with bad luck it would work at the workshop (bad luck unfortunately is common on these cases).

 

[zerocool]

the blend flap motors will throw up a fault code if there is a problem
normally they break around the lever/gear mechanism as they are only plastic
although I had a 164 ml which had very erratic heating problems,and it turned out to be the heater motor corrupting the lin bus system