heat coming in to veh thru ac vents on 1998 Toyota Avalon

i am getting heat thru the ac vents even with the thermostat down and all controls off i cannot stop the heat no matter what the controls are set on

Asked by for the 1998 Toyota Avalon
1 answer
This sounds very much like a defective blend door. The blend door is what directs the air either over the heater core for heating or the a/c evaporator for cooling. It sounds like your blend door is stuck, for some reason in the heat mode. here are some shops for repair: