Constant heat at floor even with all climate controls off

Howdy Gang:

I searched the forum and couldn't find a past topic that deals with this exact challenge. With the entire climate control off, I still get heat at the floor center. Not a major gush, but you can certainly feel it. Has anyone had this same experience so I can pinpoint what valve or electronic piece it may be that is causing this?

Thanks,

It's air venting from outside the car through the HVAC system. The solution is to turn the temperature down before shutting off the climate control. Then the air will be cooler.

Does the AC work correctly when it is on?

Yes, A/C working fine and all other functions of climate control.

To access the heater shutoff mechanics, you have to pull the dash support out. It is on the back side of the module. I am not sure why it is blowing heat when it is off, but the only part that controls the heat shutoff is the vacuum motor on top of the module.

Gastt wrote:

It's air venting from outside the car through the HVAC system. The solution is to turn the temperature down before shutting off the climate control. Then the air will be cooler.

What he said. What temperature do you have it set at?

The temp was set at 72 but I shut the system off. Sounds like it may be the module that Fred referenced. I shut the heater as it is hot out yet hot air still coming from floor vent.

Wagoninabox wrote:

The temp was set at 72 but I shut the system off. Sounds like it may be the module that Fred referenced. I shut the heater as it is hot out yet hot air still coming from floor vent.

Run it down to 60 then shut it off and see what happens before you tear it apart.

I was not referring to the heater module, but the vacuum manifold may have an issue. The only way you are going to find the issue is to start pulling parts, and swapping them, unless you have an FSM and the diagnostics.

Okay. Ill try the lowering of the heat and shutting off, but that seems odd as I have never had to do that in any car before. I will report back once I find a solution. I may be pulling the dash and swapping parts as Fred mentioned to pinpoint this issue.

Wagoninabox wrote:

Okay. Ill try the lowering of the heat and shutting off, but that seems odd as I have never had to do that in any car before. I will report back once I find a solution. I may be pulling the dash and swapping parts as Fred mentioned to pinpoint this issue.

Maybe but try the simple things first My car will "flow" warm air through the floor if I leave the temperature set to something warm so I make sure to lower it to 60 before I shut it off. Maybe we have the same problem

All these b bodies allow air to flow through with the havac off. Everyone I had did anyway. (10+) If you leave the temp high the air will be hot.

Wagoninabox wrote:

Howdy Gang:

I searched the forum and couldn't find a past topic that deals with this exact challenge. With the entire climate control off, I still get heat at the floor center. Not a major gush, but you can certainly feel it. Has anyone had this same experience so I can pinpoint what valve or electronic piece it may be that is causing this?

Thanks,

Well, what did you find?

GN120- have not yet as the wagon has been sitting in my mechanics yard awaiting tune up. I have asked him to give the heat issue a look after the engine work. I will update as soon as I get it back. I'm taking it on a long road trip when back so I'll know if the "turn the heat down before turning off" thing works.

Still nothing?

GN1220 is correct. I found that whatever temp you shut the system off at, it will still allow slight pass through at that temp at the floor. I am just not used to this when living in the upper northwest, but it is more apparant here in Nevada. The mornings start cool here, then can get very warm, then cools off again. I may have the heat on when I am driving on a cool day and shut it off. When I drive again, the car is hot while driving because it is allowing in warmer air. Looks like I am just going to have to get used to this. One thing I am impressed about is the fairly robust climate controls in our Buicks!

Wagoninabox wrote:

GN1220 is correct. I found that whatever temp you shut the system off at, it will still allow slight pass through at that temp at the floor. I am just not used to this when living in the upper northwest, but it is more apparant here in Nevada. The mornings start cool here, then can get very warm, then cools off again. I may have the heat on when I am driving on a cool day and shut it off. When I drive again, the car is hot while driving because it is allowing in warmer air. Looks like I am just going to have to get used to this. One thing I am impressed about is the fairly robust climate controls in our Buicks!

Glad you figured it out and it didn't cost a fortune to fix!