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2015 chevy 1500.. 3400 miles. A couple of times the heat didn't work. It always did "next time".. the other day I had to take a 3 hour drive.. it didn't work the whole way there...stopped for an hour..headed back still with no heat (it was 42* so it was not pleasant)


Took to dealer - they said they cant find anything wrong, of course, and of course the he was working fine.


Its only done this a couple of times in the past 2 months now.


Anyone experienced anything similar? It blows out air, and it will adjust the fan speed properly (or what I'm guessing WOULD be properly if it was blowing out heat) based on the temp of the cab. Even when taken off of auto and just turned temp to hi and fan speed up, with AC button off, it was still blowing cold air.


Any ideas? Could it somehow be user error? (doubtful)


Also when the AC button is on, even when its on heat, is the AC really still running? seems dumb that lights always on even when you have the temp high and its blowing heat.

Edited by twentythreemx
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If you have not had the HVAC module updated get that done first. Mine was the same way, heat had to be turned to 80° before I would get heat, or if I turned the system off and then back on it would produce heat. Also yea if you have the AC the compressor is running as it will be pulling humidity from the air.

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Also yea if you have the AC the compressor is running as it will be pulling humidity from the air.

When you have the defroster on the AC runs by default. At least it did on mine. Remote start fires up the defrosters when cold, so the AC was running. This blows dry air on the windshield to get it defrosted faster.

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  • 4 months later...

Just wanted to bump this post back up from the dead. I have not had a single problem with my heat all winter long. Now that temps have started to warm back up, I had this issue today for the first time since probably posting this or shortly after posting it (4+ months ago)


Wondering if its something to do with this certain temperature (it was about 39 this morning when it happened) and temps would have been similar when this originally was happening.


Anyways, it was a cold ride to work this morning. Took it to dealer before when I had problems and of course they couldn't find anything wrong.

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  • 4 years later...

Hello Everybody,


I have a 2018 GMC sierra denali 6.2L, and a few weeks now, the heating and A/C is not working.

When I put it into manual blowing, and not automatic, I hear the blower start and shortly after stops.


Does anybody know what the cause is of this problem?

The garage here, have connected the car to the computer, but no errors or whatsoever.


Sorry for my bad english, i am from belgium!

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