LG Dryer d80, d90, d95: FlowSense Vent Blockage Fix

FlowSense is LG’s proprietary exhaust monitoring system that detects lint buildup before it becomes a fire hazard. These codes are unique to LG dryers and represent the most commonly searched dryer error codes.

Understanding FlowSense Codes

FlowSense uses sensors that monitor backpressure and temperature in the exhaust system. When lint restricts airflow, heat builds up and triggers progressive warnings.

Code	Blockage Level	Dryer Behavior	Action Required
d75	75% blocked	Continues running	Schedule cleaning soon
d80	80% blocked	Continues but inefficient	Clean vent system
d90	90% blocked	Enters cool-down, stops	Stop using; clean immediately
d95	95% blocked	Shuts down immediately	FIRE HAZARD—professional cleaning

FlowSense Bar Indicators

Some models show bar indicators instead of (or alongside) codes:

Display	Meaning
No bars	Airflow normal
2 bars	Moderate restriction—clean soon
4 bars	Severe blockage—clean immediately

Fire Safety Warning

Dryer vent blockages are a serious fire risk:

• ~15,000 dryer fires annually in the US
• 34% caused by lint buildup in vents
• 92% of laundry fires caused by dryers (not washers)
• Peak occurrence: January, 1-2 PM

Warning signs of fire hazard:

• Clothes take longer than one cycle to dry
• Dryer exterior unusually hot to touch
• Burning smell during operation
• Exterior vent flap doesn’t open during operation
• Visible lint around dryer connections

d80 — 80% Duct Blockage

What It Means

The dryer detects significant lint buildup restricting approximately 80% of airflow. The dryer continues operating but inefficiently.

Symptoms

• Clothes still damp after normal cycle
• Dryer exterior feels hot
• Weak airflow at exterior vent
• Extended drying times

Gas Dryer Note

On DLG/DLGX gas models, d80 may indicate lack of gas supply rather than duct blockage. If the gas valve is closed or gas service is interrupted, the dryer may misinterpret this as airflow restriction.

Check: Verify gas valve is fully open (handle parallel to pipe) and other gas appliances work before assuming duct blockage.

Fix Steps

1. Clean lint filter with warm water and soft brush
2. Pull dryer from wall and check exhaust hose for crushing or kinks
3. Verify hose follows straight path or gentle S-curve
4. Check exterior vent and remove visible lint
5. Run Air Dry cycle while checking exterior for airflow
6. Replace foil duct with semi-rigid metal if needed

d90 — 90% Duct Blockage

What It Means

Severe airflow restriction detected. The dryer automatically enters cool-down mode and stops to prevent fire.

Action Required

Stop using the dryer until the vent system is thoroughly cleaned.

Fix Steps

1. Clean lint filter thoroughly
2. Disconnect and inspect transition duct behind dryer
3. Use vent brush kit (20+ feet) to clean entire run
4. Check exterior vent for bird nests, debris, or collapsed ductwork
5. Consider professional vent cleaning if ductwork is in walls

d95 — 95% Duct Blockage (CRITICAL)

What It Means

Near-complete blockage requiring immediate attention. The dryer shuts down immediately as a safety measure.

This is a fire hazard. Do NOT operate the dryer.

Action Required

1. Unplug dryer immediately
2. Do not attempt to run any cycles
3. Contact professional vent cleaning service
4. Request they verify vent length and elbow count
5. Do not use dryer until cleared by professional

LG Vent Length Specifications

Your vent run may be too long, causing FlowSense alerts even with clean ducts.

Maximum Duct Lengths (4-inch diameter)

90° Elbows	Maximum Length
0 elbows	65 ft (19.8 m)
1 elbow	55 ft (16.8 m)
2 elbows	47 ft (14.3 m)
3 elbows	36 ft (11.0 m)
4 elbows	28 ft (8.5 m)

Rule: Deduct 6 feet per 90° elbow from maximum length.

Maximum elbows: 4

Flexible metal duct: Limited to 8 feet total

Prohibited Configurations

-Plastic or vinyl ducting (fire hazard) -Thin foil ducting (crushes easily, creates turbulence) -Kinked, crushed, or coiled ductwork -Screens or mesh over exterior vent (clogs with lint) -More than 4 elbows -Vent runs exceeding adjusted length limits

False FlowSense Alerts

If codes persist after thorough cleaning:

Common Causes of False Positives

1. Faulty thermistor sensor (Part #6323EL2001B)
2. Dirty airflow sensor inside dryer
3. Vent run exceeds length limits (even if clean)
4. Too many elbows creating turbulence
5. Testing with wet clothes (test with dry load or empty)

Diagnostic Test

Run the dryer with the vent completely disconnected (outdoors or garage only—lint will blow out).

• If code clears: Problem is in the ductwork
• If code persists: Sensor or internal issue—service needed

Clearing FlowSense Codes

FlowSense codes automatically clear once airflow is restored. There’s no manual reset required.

If codes persist after cleaning:

1. Perform factory reset (unplug, hold POWER 5 seconds, hold PLAY/PAUSE 5 seconds, restore power)
2. If code returns immediately, blockage not fully cleared or sensor faulty

Model Coverage

FlowSense applies to:

• Electric (DLE/DLEX): All models with FlowSense feature
• Gas (DLG/DLGX): All models—note d80 gas supply caveat
• WashTower (WKEX/WKGX): Same codes apply

Does NOT apply to: Heat pump dryers (DLHC)—these are ventless

Maintenance Schedule

Usage Level	Cleaning Frequency
Light (1-2 loads/week)	Annually
Normal (3-5 loads/week)	Every 6-9 months
Heavy (daily, pet owners)	Every 6 months

Always: Clean lint filter after every load.

When to Call a Professional

Contact a vent cleaning service or LG support (1-800-243-0000) if:

• d90 or d95 codes appear (fire hazard)
• Ductwork is inaccessible in walls
• Vent run exceeds 25 feet
• Code persists after thorough cleaning
• You cannot verify exterior vent airflow

Professional vent cleaning cost: $100-200 typically

Sources

For official LG support:

• LG FlowSense d90/d95 Guide
• LG Dryer Error Code List
• LG Dryer Venting Requirements

Related Guides

• LG Dryer Error Codes: Complete Guide
• How to Reset an LG Dryer
• LG Dryer Vent Requirements