Heater always blowing hot air

[GMC5.0]

Heater works very well except when you turn it off, both the front and the rear controls. When off hot air still comes out of dash and floor vents.

Also, does any company offer a repair manual for the 01' yukon xl

[GMC5.0]

I guess I should have put in my post that its a 2001 Yukon XL SLT, 5.3, power everything.

[TGARST]

Turn your temp down to 60 and turn off. I assume you have the auto HVAC since it's a SLT. The HVAC is still circulating HOT water thru heater core if it's on like 90 even when off.
just a thought
Tim

[bennybenster]

Are you moving when this is happening?

If you are and your vents are open and your temp is at 90, then yes, hot air will sill come out of the vents. If you have it set so that the air comes out of the the floor and the defroster vents, you won't be able to close the vents. You have to choose the "face" vents and then choose the circulation button so that the front vents close. You won't feel anymore air coming in if you do that.

[GMC5.0]

Originally Posted by TGARST

Turn your temp down to 60 and turn off. I assume you have the auto HVAC since it's a SLT. The HVAC is still circulating HOT water thru heater core if it's on like 90 even when off.
just a thought
Tim

This SLT does not have the Auto SLT, it has the regular dial switches. I've tried shutting it down several different ways and it still blowes hot air. I've even turned the A/C on and it seems the air is cool instead of cold. (Almost like the heater and A/C were running at the same time.)

[GMC5.0]

Originally Posted by bennybenster

Are you moving when this is happening?

If you are and your vents are open and your temp is at 90, then yes, hot air will sill come out of the vents. If you have it set so that the air comes out of the the floor and the defroster vents, you won't be able to close the vents. You have to choose the "face" vents and then choose the circulation button so that the front vents close. You won't feel anymore air coming in if you do that.

This is occurring when I'm moving or sitting still. I've tried shutting it down several with several different configurations.

[GMC5.0]

Originally Posted by bennybenster

Are you moving when this is happening?

If you are and your vents are open and your temp is at 90, then yes, hot air will sill come out of the vents. If you have it set so that the air comes out of the the floor and the defroster vents, you won't be able to close the vents. You have to choose the "face" vents and then choose the circulation button so that the front vents close. You won't feel anymore air coming in if you do that.

Did you read my reply??

[rickefel]

Originally Posted by GMC5.0

Heater works very well except when you turn it off, both the front and the rear controls. When off hot air still comes out of dash and floor vents.

Also, does any company offer a repair manual for the 01' yukon xl

I Have the same problem, it seems when you drive with your heat on for about a 1/2 hour or more it doesnt shut down or cool down. also my control dial for the blower doesnt work on setting 1. I thought that this could be my problem, that the unit needed to be replaced and maybe this would cure the problem.

[GMC5.0]

Originally Posted by rickefel

I Have the same problem, it seems when you drive with your heat on for about a 1/2 hour or more it doesnt shut down or cool down. also my control dial for the blower doesnt work on setting 1. I thought that this could be my problem, that the unit needed to be replaced and maybe this would cure the problem.

I read the owner manual some more and found that there are several different settings for the heat and fan and that some of them are almost automatic. It seems from what I read that really the blower or air is circulated thru the vehicle at all times unless you do a shut down sequence. Again you have to read the manual, it's worked on mine since I've posted this. Good luck.

[horse482]

Welcome to the world of gm, all gm pickups and suv's for the last 15-20 years have done this. Unlike most other vechile makers gm doesn't turn off the hot water running through the heater core when the heater is turned off.

[GMC5.0]

So Horse, is there an after market product that can be installed to secure the hot water going to the heater core during the summer? Doesn't this put a heavier load on the A/C or at least doesn't cool as well as it should.