I have been getting very little heat in my car for a while now. It takes forever to heat up. I have had the radiator replaced, as well as the thermostat. I just had the thermostat replaced and now its just blowing cold air. I let it run for about 5 mins before I got in, drove it for about 15 minutes and it was blowing nothing but cold air. Temp gauge goes up to the normal level. Any ideas of what could be wrong? I got the heater core checked, they said all was good, suggested the thermostat, which I then got replaced. It seems that the air was at least lukewarm before I got the thermostat replaced, now its just cold.

 

The controls are probably bad or the flap inside the heater box is stuck on cold.