My 95 E300D just started having heat problems. I changed the thermostat and flushed the collant system and that did nothing to help my problem. I think I may know what my problem is but I wanted to get a second opinion before I ordered the expensive part. I was checking around the car trying to see if I could determine the problem and I began looking at the heater control valve, the heater hose going into the valve is warm then there are three hoses coming out of the valve, the top hose was warm but the bottom two hoses were cold, not warm at all. My question is aren't all the hoses going in and out of this heater control valve supposed to be warm? If so, I must have a faulty heater control valve. I know Mercedes W123 cars are known for their monovalve that tend to go out and take away heat or air, but I have not heard about many W124 having this problem. Just wanted to check with someone more knowledgable than myself because from what I am finding the 1995 E300D has a special heater control valve that is pretty pricey.