volvodoc

Since new the heater has not seemed right. With floor button on it seems like to much hot air is in the upper part of the cabin.Yes I know hot air rises. Today while driving,the sound of the fan changed like the recirculated door closed.then went back to normal. Any thoughts??

platinum99

[QUOTE=volvodoc;5117096]Since new the heater has not seemed right. With floor button on it seems like to much hot air is in the upper part of the cabin.Yes I know hot air rises. Today while driving,the sound of the fan changed like the recirculated door closed.then went back to normal. Any thoughts??[/QU


Mine does this sometimes as well

Gulleyrw

I have noticed this but thought it had something to do with the speed. When I slow or stop it sounds like it switches to and from cabin air.

Maybe i am crazy tho

majahack

I hear the switching noise quite a bit in my 2016 XL S-Cab. You still might be crazy but at least you have company.

BlackBoost

The HVAC does certain things on its own to regulate temperature and humidity. If you have your defrost on, it kicks on the AC compressor to dry out the air. If it's cold in the cab and you have the heat on, it can switch to recirc mode whether you like it or not until the temperature goes up. I also think, at least with my 2.7, it keeps it in recirc mode when the engine is cold until it's warmed up a bit so the engine can warm up faster. Cold outside air running through the heater core will make the coolant colder which will make it take longer to warm up.

motorhead2013

Interesting, thanks for the info. I noticed mine doing that a few times.

V8-Coyote

The AUTO HVAC system will recirc when in reverse, not sure if it recircs during windshield washing like a lot of AUTO HVAC systems do (my Audi and VW do both)

Indy2015

Same thing here. I normally run my fan speed very low, so I don't notice changes in air direction very much. But the other day it was colder than normal and I had the fan speed on high, and twice I heard an air box door change position. I couldn't determine if or in what way the air was re-directed.

cal50

iTrader: (1)

My heating system does things its own way as well.......
I think the buttons and lights on the control panel are just there to appease the operator.

Magnetic157

I've noticed mine a few times automatically make the air sound as if re-diric was turned on (makes a higher distinct blower noise) but the light was still off. I clicked the botton so the light turned on and there was no different sound. Click it again so the light is off and it goes back to the normal air sound.

Almost like the door opened up without the dash indicating so.