Burning up, heater control not functioning?

Hi all, new to the forum and hoping someone can help me solve a problem with my 01 Burb. The problem mostly rears it's ugly head in the winter when we use the heat. Our truck is an LE and has the Blue/Red style temperature selector on the front heat/ac controls. The problem is if you turn the temp. selector to hot you cannot get the system to return to cool / cold air, it just continues to blow extremely hot air. Even if you turn the blower to off it still puts out enough hot air to make it extremely uncomfortable. We end up putting the rear air on vent and blowing cold air towards the front.

Sometimes if you turn off the truck for awhile and set the dial to cold it will blow cold/cool air until you need to increase the temp again and then you're stuck with the truck blowing hot air no matter what you try. I recently replaced the front control module, but that didn't seem to do a thing. I'm wondering if this is a common problem in the 01's as my brother-in-law has the same problem in his 01 Silverado pick-up. Any help would be greatly appreciated.

I have the same exact problem on my 2000.5 tahoe. I wish someone out there knew what was causing this.

Hi all, new to the forum and hoping someone can help me solve a problem with my 01 Burb. The problem mostly rears it's ugly head in the winter when we use the heat. Our truck is an LE and has the Blue/Red style temperature selector on the front heat/ac controls. The problem is if you turn the temp. selector to hot you cannot get the system to return to cool / cold air, it just continues to blow extremely hot air. Even if you turn the blower to off it still puts out enough hot air to make it extremely uncomfortable. We end up putting the rear air on vent and blowing cold air towards the front.

Sometimes if you turn off the truck for awhile and set the dial to cold it will blow cold/cool air until you need to increase the temp again and then you're stuck with the truck blowing hot air no matter what you try. I recently replaced the front control module, but that didn't seem to do a thing. I'm wondering if this is a common problem in the 01's as my brother-in-law has the same problem in his 01 Silverado pick-up. Any help would be greatly appreciated.

I have a 2000 Burb, and have the same problem. I have not been able to figure it out. The dealer wants $200 to figure it out, I can't wait for summer!

I notice on my older burb 95' that my fresh/recycle vent was stuck open and notice it more when driving behind an older car belching smoke as we would smell this aroma, Anyway I noticed that most of the A/C Heat controls on newer vehicles are controlled with vacuum swithes rather than cables, even on heater controls, I discovered I had a vacuum switch go bad which stuck the fresh air vent open every time I started the truck, I disconnected it and it went back to the recyled air position (which I don't mind). There may be a vacuum switch going bad and perhaps it may be listed in a TSB . Otherwise I'd try to locate the vacuum switch that opens and shuts/opens the heat valve/door/? and see if that 's the prob, believe me this stuffs hidden or way up in the dash so good luck.

After researching some more, I found that the problem is with the flapper conrol mechanism. It's controlled by an electrical actuator. This actuator needs to be replaced because the flapper when turned to 100% Heat gets stuck and the actuator is too weak to move it off of it's seat. Sometimes you can get lucky and it will unseat after being turned off and cooled down. It's located under the glove box and costs about $60 from the dealer or $40 from online discount stores. I have found personally that if I never go to 100% Heat, it never get's stuck, & at 95% Red, I get more heat than I need. I will probably change out the part eventually, but since figuring out the 95% rule & convincing my wife not to go to 100%, I haven't had a single problem with it & I have full control of the temperature.

Part number for 2000 tahoe is 52474810
after market acdelco part number 15-72507

Hope this helps.

Your right I previously disconnected my actuator for the fresh/recyled air vent, It was not closing the vent so I constantly recived "fresh" smog from outside! I simply disconnected it and the problem went away. Sorry you can't do that for the heater though. Maybe in the summer? or just by the part, I had forgotten this was done til a few posts ago.