LG Dryer Flow Sense Light – Meaning, Causes & Fix
The "Flow Sense" indicator on an LG dryer illuminates when the appliance detects a restriction in the exhaust airflow, meaning moist air isn't escaping the drum and venting outside as efficiently as it should. LG dryers include this sensor-based monitoring system to alert users to reduced airflow before it causes longer drying times, increased energy use, or a potential safety hazard from lint buildup. This guide explains what triggers the Flow Sense light and how to resolve it. For related appliance indicator issues, see our Bosch Dishwasher Check Water Light guide and our Samsung Dryer Cooling Light guide.
What it means
The dryer has detected restricted exhaust airflow, most commonly caused by a clogged lint filter, blocked or kinked vent duct, or an obstructed exterior vent hood.
Severity
ModerateCan you fix it yourself?
Yes — cleaning the lint filter and inspecting the vent duct is straightforward and requires no special tools.
Call a technician when
Contact a professional vent cleaning service if the ductwork is long, inaccessible, or the Flow Sense light persists after filter and accessible duct cleaning.
What Does Flow Sense Light Mean?
LG dryers use sensors to monitor the rate at which air flows through the drum and out the exhaust. When this airflow drops below a threshold — typically due to lint accumulation or a physical obstruction in the vent path — the Flow Sense light illuminates to alert the user that drying efficiency is compromised and a safety risk may be developing.
Common causes include:
1. Clogged lint filter: The most common and easiest-to-fix cause; a lint filter that hasn't been cleaned after each load restricts airflow immediately. 2. Blocked or kinked vent duct: The flexible or rigid duct connecting the dryer to the wall vent can become kinked, crushed, or clogged with lint over time. 3. Lint accumulation in the ductwork: Over months and years, lint builds up inside the vent duct run inside walls or attics, progressively restricting airflow. 4. Obstructed exterior vent hood: The outside vent hood can become blocked by lint, debris, bird nests, or snow. 5. Overly long or complex vent run: Vent ducts that exceed the manufacturer's recommended length or include many bends reduce airflow even when clean.
This airflow-monitoring indicator functions similarly to the Samsung dryer Cooling light as a sensor-based alert designed to prompt preventive maintenance before a more serious problem develops.
What Causes This Error?
- Clogged lint filter not cleaned after each load
- Kinked, crushed, or damaged vent duct between the dryer and wall
- Lint accumulation inside the vent ductwork over months or years of use
- Exterior vent hood blocked by lint, debris, animal nests, or snow
- Vent run exceeding the manufacturer's recommended maximum length or with too many bends
- Flexible foil or plastic vent duct material that sags and traps lint
- Blocked or restricted airflow around the dryer's rear clearance area
How to Fix Flow Sense Light
- 1
Clean the lint filter thoroughly before every load. Remove the lint screen from its slot, peel off all accumulated lint, and rinse it under water if needed to remove fabric softener residue that can restrict airflow through the mesh.
- 2
Disconnect and inspect the vent duct behind the dryer. Pull the dryer away from the wall, disconnect the vent duct at both the dryer and wall ends, and check for kinks, crushing, or visible lint buildup. Clean out any lint and reconnect with a smooth, uncrossed duct path.
- 3
Check the exterior vent hood outside the home. Walk outside to where the dryer vent exits the house and confirm the vent hood opens freely and isn't blocked by lint, debris, snow, or animal nests. Clear any obstruction carefully.
- 4
Replace any flexible foil or plastic duct with rigid or semi-rigid metal duct. Flexible plastic or foil ducts sag and trap lint; rigid or semi-rigid metal duct provides smoother airflow and is also a safety requirement in many building codes.
- 5
Run a test cycle and observe whether the Flow Sense light clears. After cleaning the filter and accessible duct, run a short cycle to see if the light turns off. If it remains on, the restriction is likely deeper in the ductwork.
- 6
Schedule a professional vent cleaning if the light persists. If the accessible duct and exterior vent are clear but Flow Sense stays on, hire a professional vent cleaning service to clear lint from the full length of the duct run inside walls or attics.
When to Call a Professional
If the Flow Sense light remains on after cleaning the lint filter, accessible duct, and exterior vent, contact a professional dryer vent cleaning service to clear the full duct run. Professional vent cleaning typically costs $100-$200 and should be done annually for normal use. Restricted airflow is a leading cause of dryer fires, so don't ignore a persistent Flow Sense indicator.
Can You Still Use the Device?
An LG dryer with the Flow Sense light on will still run and dry clothes, but drying times will be longer and energy use higher due to the restricted airflow. Because restricted airflow is a fire hazard with lint buildup, it's important to address the cause promptly rather than continuing to use the dryer extensively with the light on.
Official Resources
Disclaimer: This article is for informational purposes only and does not constitute professional repair advice. CodeExplain is not affiliated with LG or any other brand mentioned. Always consult a qualified technician for complex repairs.