Good Afternoon,

This forum has been great and I have learned quite a bit about my new to me E300TD.

I have followed the Climate Control threads closely and have searched for my particular fault without success.

My AC appears fine and works without a problem. I have recorded actual values and pulled codes through the system without a problem. Nothing unusual.

The Defrost works and pumps heat out without issue.

When I call for heat only (78 or 79 F) and the car fully warm, I feel cool, ambient air flowing, not heated air. This morning, I tapped my Duo valves to see if they were stuck and I had warm air for my trip into work. However, the ride home produced no heat. I will wait till it cools down before disassembling the duo valves to see if they are stuck. This car had one replaced in July of 2005 (new).

No abnormal fault codes - the K2 communication error and the E 'FF' code which I don't know what that is.

I wonder, since I get defrost heat, if I am looking at a door actuator failing?

Your thoughts are most appreciated.

Thank you,

Frank