AC Rest Button Question
10-24-2021, 07:12 PM
#1
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2021 GLE 53 AMG
AC Rest Button Question
Greetings everyone! First post, long time lurker. Just curious if everyone leaves the “AC Rest” button on all the time? Thanks!
Last edited by Armus7; 10-24-2021 at 08:15 PM.
10-24-2021, 08:46 PM
#3
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Mine is on just about all the time as I have the HVAC in auto mode. I've turned it off just a couple of times to bring in fresh air to hopefully lessen the potential for the future musty smell. Will see if it stays on in the winter time as my former vehicle (Ford Explorer) only kicked the compressor/AC on at 58 degrees and above
10-24-2021, 10:35 PM
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2021 GLE 53 AMG
Thanks for all your responses!
I’ve been turning mine off every time I park for a long period of time. Just don’t want to build up that musty odor that developed in my GLE 43 and other cars I own.
I’ve been hearing conflicting stories about the AC Rest button. My dealership advised me to leave it on so the system will stay on (after I turn off the car) and blow air through the evaporator coils, vents, etc.; drying everything out.
Just curious what everyone else is doing and if leaving it on works, I might give it a shot. One less thing to do.
I’ve been turning mine off every time I park for a long period of time. Just don’t want to build up that musty odor that developed in my GLE 43 and other cars I own.
I’ve been hearing conflicting stories about the AC Rest button. My dealership advised me to leave it on so the system will stay on (after I turn off the car) and blow air through the evaporator coils, vents, etc.; drying everything out.
Just curious what everyone else is doing and if leaving it on works, I might give it a shot. One less thing to do.
10-25-2021, 07:27 AM
#5
My system is on AUTO and I don't touch it. Vehicle is over 2 years old now and never had a musty smell.
10-25-2021, 09:13 AM
#6
Super Member
I think there is some confusion on how the AC/REST button works, because it is a dual purpose button.
When driving, it turns on and off the AC. This should generally be kept on to either cool the cabin in warm temperatures or dehumidify the air in cooler temperatures.
With the engine shut off, this will act as the Residual Heat button, and will turn on the fan and if in cooler temperatures, will divert some of the engine heat into the cabin. After a period of time or once you start the car, there Residual function is deactivated.
So no reason to touch that button when you park, unless you want to activate the residual heating function.
Where this gets extra confusing, is that Mercedes has an evaporator drying function to dry out the evaporator to prevent the smells mentioned which will run the fan on low after the car is shut off. This can seem exactly like the REST function if you are around when it happens.
When driving, it turns on and off the AC. This should generally be kept on to either cool the cabin in warm temperatures or dehumidify the air in cooler temperatures.
With the engine shut off, this will act as the Residual Heat button, and will turn on the fan and if in cooler temperatures, will divert some of the engine heat into the cabin. After a period of time or once you start the car, there Residual function is deactivated.
So no reason to touch that button when you park, unless you want to activate the residual heating function.
Where this gets extra confusing, is that Mercedes has an evaporator drying function to dry out the evaporator to prevent the smells mentioned which will run the fan on low after the car is shut off. This can seem exactly like the REST function if you are around when it happens.
