Chevy Suburban Front Heater

The front heater in my 2001 Chevy Suburban is blowing air but does not get hot (or even warm!). The rear heater works fine. What could be the problem?



You could be having trouble with a faulty mode switch or a faulty blend door/motor.

The temp knob is not spinning on the shaft is it? I have repalced so many of thes HVAC heads for a host of problems,then again it could be a blend door issue. The fauilure is that all air must be being diverted around the core,hmm.