Dryer Vent Cleaning Brush Kit
Rotary brush kit to clean the full duct run from wall to exterior.
$25
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D80 on an LG dryer means LG’s FlowSense technology detected that your exhaust duct is 80% blocked. Stop using the dryer until the vent is cleaned. A heavily blocked vent is one of the leading causes of home dryer fires — LG’s sensor is warning you about a real hazard.
Quick Reference
| Code | Meaning | Severity | DIY or Call |
|---|---|---|---|
| D80 | Duct ~80% blocked | High | DIY — clean now |
| D90 | Duct ~90% blocked | High | DIY — urgent |
| D95 | Duct ~95% blocked | Critical | DIY — stop use |
D80 = 80% blocked. D90 = 90% blocked. D95 = 95% blocked. The higher the number, the more urgent.
What This Error Means
LG dryers with FlowSense monitor airflow through the exhaust system using a sensor that detects how efficiently air moves from the drum through the duct and out of the house. When blockage reduces airflow by 80% or more, the D80 warning appears.
Unlike some error codes that stop the machine, D80 is initially a warning — the dryer may still run. But continuing to use it with a severely blocked vent risks overheating, compounded lint buildup, and eventually fire.
Common Causes
- Lint accumulation in the duct — The main cause. Lint builds up inside the duct over months and years. The longer the duct run and the more bends it has, the faster it accumulates.
- Crushed flexible duct — The accordion-style foil duct behind the dryer gets crushed when the dryer is pushed too close to the wall, dramatically restricting airflow.
- Bird nest or debris at exterior vent — Birds nest in exterior vent caps. The nest blocks airflow completely.
- Flap stuck closed on exterior vent — The exterior vent flap can get stuck shut from paint, ice in winter, or lint glued around the hinge.
- Duct run too long or too many elbows — Maximum duct length is typically 25 feet of straight rigid duct; each 90° elbow subtracts 5 feet from the allowable run.
Step-by-Step Fix
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Clean the lint trap completely. Pull it out and run it under the faucet — if water beads on the screen, wash with dish soap and a brush. A coated lint screen reduces airflow measurably.
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Pull the dryer away from the wall. Disconnect the dryer from the electrical outlet (or gas supply valve) before moving it.
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Disconnect the duct at the back of the dryer. Remove any clamps or tape holding the duct to the dryer outlet collar.
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Clean from the dryer end. Push a rotary vent brush kit through the duct toward the house wall, rotating as you go to break up lint. Work in sections, pulling out what you dislodge.
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Clean from the exterior. Go outside, remove the vent cover, and clean from that end too. Use the brush kit from outside in, then from inside out.
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Check duct condition. If the flexible duct is crushed, torn, or heavily compressed, replace it. Rigid metal duct is much better — it stays cleaner, lasts longer, and reduces lint buildup. The transition from the dryer to the wall can use a periscope-style connector to gain clearance in tight spaces.
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Reconnect and test. Push the dryer back, reconnect the duct and power. Run a timed dry cycle. D80 should clear if airflow is restored. If D80 or D90 still appears after a thorough cleaning, the FlowSense sensor may have failed.
Parts You May Need
- Dryer vent cleaning rotary brush kit
- Rigid aluminum dryer duct kit
- Dryer periscope vent connector
- Exterior dryer vent cap with flap
When to Call a Technician
If D80 persists after a thorough vent cleaning, the FlowSense sensor inside the dryer may have failed. An appliance technician can test the sensor and replace it. Long or complex duct runs through walls or attics may also need a professional duct cleaning service with commercial equipment.