Lancer temperature dial knob problem

I have a 2003 lancer. I turned the knob cold for a/c, stays.and I get a/c. But if I turn to heat but I get no heat but cold air and the knob does not stay at the red heat lines. It moved. What is the matter?

I don't remember if it was the temp knob or the mode knob but there is a TSB about one of the knobs being hard to turn. You have to replace one of the doors and clean/modify the heater box a bit.

Thank you. I discovered the problem.. The cable the connects to the lever is bent. It is bent because the lever is stuck or jammed as there could be accumulated dust that prevents the lever to operate properly. I will clean it out.