AZ Dryer Pros · October 15, 2026
It means the dryer has sensed that air isn't leaving as freely as it should, somewhere between the dryer and the outside hood. The blockage can be lint in the duct, a crushed hose, a stuck flap or a nest. Clean the lint screen and check the hose and outside flap first; if the warning comes back, the vent needs cleaning.
What the warning is
Many newer dryers watch their own airflow and warn you when it drops. The feature goes by different names. Consumer Reports has described Check Vent and Airflow Alert indicators on Whirlpool and Maytag dryers, FlowSense on LG dryers and Vent Sensor on Samsung dryers. Your manual will name yours.
LG's support material describes its warning plainly: airflow is restricted somewhere between the dryer and the outside exhaust exit. That's a useful way to read any of these lights. It's not telling you which part is blocked, only that the path is.
What to check first
Work from the dryer outward:
- Clean the lint screen, and wash it if it looks coated
- Pull the dryer out and look at the hose behind it: crushed, kinked, torn or squashed against the wall
- Make sure the hose is still attached at both ends
- Go outside with the dryer running and check that the hood flap opens fully
- Look for lint, dust, a nest or, up north, snow or ice at the hood
If the warning keeps coming back
If the screen is clean, the hose is fine and the flap opens, the restriction is most likely inside the duct. That needs a cleaning of the full run, from the dryer to the outside hood.
A standard cleaning is $79. A badly packed or long run starts at $129, and roof or second-floor vents start at $199. A crushed hose is replaced from $149. You get the exact price before any extra work.
Some runs are simply long or have many elbows. A clean but long vent can still restrict airflow enough to trigger a warning. In that case the technician will tell you whether rerouting, from $399, or a booster fan, priced on site, would help.
Don't rely on the light alone
Consumer Reports tested these indicators by blocking vent ducts. They caught fully blocked vents more reliably than partly blocked ones. A partly clogged vent can go a long time without a warning while drying times creep up.
So treat the light as one signal, not the only one. If your loads take longer or the laundry room is hotter than it used to be, check the vent even if the dryer hasn't complained. And keep to an annual cleaning regardless.
The opposite also happens. After a cleaning, the warning should stop. If it doesn't, the cause is usually something a brush can't fix: a crushed section of duct inside a wall, a disconnected joint in the attic or a cap with the wrong kind of screen. Those are found with an airflow reading and a look along the run.
Should you keep using the dryer?
LG's manual says not to use the dryer when a restriction is sensed until the exhaust system has been cleaned or repaired. That's sound advice for any brand. A blocked vent makes the dryer run hotter, and lint is the fuel in most dryer fires.
Related: Dryer Vent Cleaning · Prices