SLK SLK250 SPORT CDI No Heat

[akranes]

Hi All.

Just joined this forum and looking for some help please.

I have a SLK250 CDI .... 14 plate. There is no heat regardless of the temperature set. Its only blowing cold air and the two center vents blow nothing at all.
The engine is up to temperature.

Does anybody have any idea what the problem might be please?

Thanks in advance

 

[wongl]

Hi All.

Just joined this forum and looking for some help please.

I have a SLK250 CDI .... 14 plate. There is no heat regardless of the temperature set. Its only blowing cold air and the two center vents blow nothing at all.
The engine is up to temperature.

Does anybody have any idea what the problem might be please?

Thanks in advance

This is likely to be your duo valve - it is located behind the radiator. I had on the same problem on mine and was preparing to clean it out or out right replace it. But before I went through the trouble of taking the valve off, I tried turning the heating full on and off several times with the engine running and warmed up. Eventually after about 10 mins of cycling the temp control from cold to max, I started getting warm air and now the heating on my SLK is fully working again.

You can try this. Good luck.

 

[akranes]

Thanks very much. I'll have a look for the valve and try your idea. I'll let you know what happens.

Cheers Marc

 

[akranes]

Hi All.

Just joined this forum and looking for some help please.

I have a SLK250 CDI .... 14 plate. There is no heat regardless of the temperature set. Its only blowing cold air and the two center vents blow nothing at all.
The engine is up to temperature.

Does anybody have any idea what the problem might be please?

Thanks in advance

Update.

It appears the heater stepper motor was accidentally disabled. A mechanic on a previous service had disconnected one of the motor electrical connections whilst replacing the pollen filter. Luckily the mechanic I took the car to discovered this quite quickly. So there you go a simple fault in the end.