Why is cold air blowing from the cabin air filtration when the heat is on high ? on 2006 Dodge Grand Caravan

The AC is turned off. It mades no differce if you vent the air to dash or floor or both at the same time.

Asked by for the 2006 Dodge Grand Caravan
1 answer
Coolant problem bad thermostat,clogged heater core , water pump..