Heater problems

[Tuscan Six]

Can anyone provide advice re. Tuscan heater? I had the motor that controls the vent from hot to cold replaced last year - it had burned out. Now I can't get hot again although I can hear the motor trying to do something when I move the heater control. I have switched it from hot to cold many times to try and unstick it as per a previous string but no joy. I have also bashed the dash and removed the ashtray!?!

Thanks

[NCE 61]

Possibly the plastic gear on the stepper motor has worn/broken teeth, which seems a common problem.