Recirculate No Workie In Cold Weather

[need-for-speed]

My HVAC system won't let me select recirculate when the ambient temp is below 50 degrees (or thereabout). Is mine the only one that does this ?

[crepitus]

i noticed this with mine on friday. a diesel pulled out in front of me with a smoke screen and i hit the button. no workey. oh it was 5 degrees out.

[Sir Dan]

yeah, same thing w/ mine. It's just GM trying to be the big "nanny" and not risk a little fog maybe, possibly, forming on the inside of your windsheild. When its cold, like under 40, the A/C compressor won't come on to dry the air so no recirc. is allowed. Over 40 degrees, the A/C comes on with recirc button whether you want it to or not.

[MarkD]

I know you cant recirculate and defrost at the same time, is this a new development?

[hockeypro1411]

No, you've never been able to defrost and recirc. However yesterday right when I started the truck (-30F) I turned on the recirc. and had the blower set on 5. It was a 2007 GMC, and when I came back out it was still the way I left it.

[need-for-speed]

Well, 3 of us with the symptom, and 1 without. wonder what the deal is ?

 

Hockeypro - is your 2007 a NBS ?

 

p.s. nice avatar !!

[iminaquagmire]

Mine works just fine. Obviously not with either of the defrost modes selected though. Do you guys have the digital climate control perhaps?

[need-for-speed]

Mine works just fine. Obviously not with either of the defrost modes selected though. Do you guys have the digital climate control perhaps?

 

Good point. Yes, mine has the (digital) dual climate control, aka - "dual cool"

[ZZ327]

yeah, same thing w/ mine. It's just GM trying to be the big "nanny" and not risk a little fog maybe, possibly, forming on the inside of your windsheild. When its cold, like under 40, the A/C compressor won't come on to dry the air so no recirc. is allowed. Over 40 degrees, the A/C comes on with recirc button whether you want it to or not.

 

 

recirculate and defrost do pretty much the same thing, They both run the AC compressor so you have to pick one or the other.

[need-for-speed]

recirculate and defrost do pretty much the same thing, They both run the AC compressor so you have to pick one or the other.

 

Agreed. But my complaint is that I like to block outside air from coming in when I drive by a turd factory or get behind a stinker vehicle. In my situations, I did not select defrost. Next time, I'll make sure the nanny didn't turn on the defrost due to cold ambient temp.

[matt3]

I noticed this a few weeks ago. It seemed to me that I couldn't recirculate while on heat. If I turn to cold (not a/c, just cold) I was able to recirculate.

[bubba33]

I have the digital climate control and mine works the same way if its cold out it will not recirculate , it goes back to fresh air. I like to have it on recirculate when I am in the city because it stinks.

[07cliffordreddog]

yeah i've noticed this too, and for safety's sake this is the way it should be. this is GM's way of doin a favor to those folks who would otherwise just have to crack a window a smidge. i have the digital climate control and if you switch to floor or defrost it automatically tursn of the recirc. you want fresh air coming in or your windows will look like its a mobile sauna pick-up. ask anyone who's a truck driver, they'll tell ya which way you want your setting in cold weather

[hockeypro1411]

Well, 3 of us with the symptom, and 1 without. wonder what the deal is ?

 

Hockeypro - is your 2007 a NBS ?

 

p.s. nice avatar !!

 

It's a 2007 Sierra Classic. Dual climate, but obviously not digital.

[Sir Dan]

When in doubt, and only as a last resort, consult owners manual!!!

 

It reads quote: "The recirculation mode cannot be used with floor, defog, or defrost modes. if recirc is selected with one of those modes, the indicator lite flashes three times and then turns off."

 

So recirc only works with the vent or bi-level mode. At long last, mystery solved.