Heating Control Issue

[mnjeepmale]

2001 Tahoe LT
So winter has arrived here and it's been a cold one over the past few weeks as everyone knows. I'm having an issue with my heater. Heater works great and is very hot as long as I turn the dial all the way up to 82. But the issue I have is if I turn it back to like 75 or so it still blows warm air then after 30 seconds it get colder. So I really am not getting heat unless the dial is all the way up to 82.

What is the cause of this or needs replacement?

 

[Joao GANDAREZ]

May i suggest a heater calibration. Search youtube if your a visual person and youll find it. Or if you can comprehend well .answers.com/2009/09/2004-chevrolet-tahoe-blows-hot-air.html not trying to me an ass but these instructioons confuse me. Seriously. if its an auto you have to firs press auto then start the process