My heater just blows out cold air. It holds water and there doesn't seem to be any problems with the water pump or the heater core. No water is leaking in the car or from under the hood.
My heater blows cold air. on 2002 Ford Taurus
Carefully feel with your hands the temperature of the heater hoses going into the heater core from the engine compartment. If both are hot, when the coolant flow should be normal. A under dash blend air circulation door may be an issue. If one is hot and the other is cold, then look to see what may be preventing coolant flow.