Wht does my heater still have hot air coming out even when it is turned off? on 1999 GMC Jimmy

My heater works fine, but when I turned it off today hot air still came out. The blowers were off and all dials turned off.

Asked by for the 1999 GMC Jimmy
1 answer
the mode door may not be closing when commanded. you need to find the door and see if it closes when turned off.

Roy