Hey all, Trying to sort out the heat on my GF's 1999 C230 Kompressor. It is the "Classic" trim level so it has the twin temp knobs and the dials for the blower and vents, not the digital climate control system fitted to many of them The passenger side previously worked fine and the heat modulated as you would expect. The drivers side has always either blown cold or hot, there is no warm section on the dial. Its like it just flips over from full cold to full hot, and now both sides are doing it. I have disassembled and cleaned the duo valve and it made no difference to the issue. I'm assuming at this point it is working as I can get either hot or cold on each side so the valves must be opening and closing. If you leave it in the middle section of the dials it will flip flop back and forth, scorching hot for a bit, then cold for a bit with no particular pattern. I've done some hunting, and some looking at the components of the system on the EPC and am thinking that it may be the actuators that control the mixing flaps in the airbox. Only thing is I can't find a way to access them, or where the vacuum manifold is for this system. All help is appreciated as I'm rather stuck at this point. P.S. This is a Canadian market car. The reason I chose to pose this question to your forum is that it is a C230 Classic model (with the rotor knob climate control). Most forums for North America are most frequented by people in the US who did not receive this model (all of theres came with the digital climate control unit as far as I'm aware). So since I've been lead to believe this system is commonplace in the UK I'm hoping you can help.