my heater wont blow hot air. changed the cabin filter. car doesnt overheat. coolant level is fine. what else could it be?

 

Verify that the temp door is working properly. If ok then your heater core is clogged. To unclog, remove both heater core hoses that go to the thermostat housing and put a garden hose to the end to flush the heater core out. When you put hose on take note of what comes out of the other hose. Usually a thick snot like glob will come out. Also reverse flush the core as well

 

Where is the temp door located?

 

Should be on the passenger side (center) of vehicle below a/c control head. With vehicle running while looking under glove box turn the temp **** back and forth and see if the actuator moves back and forth. If it moves, heater core is likely clogged. Also while doing this you can hear the tone change (air movement).