Maintenance procedure · Written to ASD-STE100 Issue 9 · Formatted to ANSI Z535

Clothes Dryer Exhaust Duct Clearing

Domestic clothes dryers vented through an outside wall — lint screen housing, exhaust duct and exhaust hood
ApplicabilityDomestic clothes dryers vented through an outside wall, where the exhaust hood is within reach from the ground
Task time27 min to 39 min editorial estimate, not a measurement
PersonnelOne
Revisionv1 · 2026-07-29
BEFORE YOU BEGIN

Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.

Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.

Summary

Lint gets past the lint trap on every load, and it settles in the duct between the dryer and the outside wall. As the duct fills, the air slows, heat builds, and the dryer runs longer to do the same work. The U.S. Fire Administration reports that failure to clean was the leading contributing factor in home clothes dryer fires between 2018 and 2020, at 31 percent of them. The CPSC is blunt about the mechanism: lint blocks the airflow, heat collects, and a fire can start.

This page covers a dryer that vents through a nearby outside wall, where the exhaust hood is within reach from where you stand on the ground. It does not cover a duct that ends at the roof, a duct you cannot reach, or any dryer that runs on gas — moving a gas dryer is how the connector behind it gets damaged, and that is a job with a professional in it. The duct cleaning interval is not printed here as a single number, because the three manufacturers we checked give three different answers and all three are named below.

Safety

WARNING

LINT IN THE EXHAUST DUCT IS A FIRE HAZARD.
A fire can start in the duct and move into the house.

Necessary equipment

ItemNote
Dryer vent brush with rodsThe brush must be longer than the duct.
Vacuum cleaner with a hoseA narrow tool for the hose helps at the opening of the duct.
Narrow brush or pipe cleanerFor the housing of the lint screen.
Screwdriver or nut driver optionalOnly if the clamp on the duct has a screw.
Flashlight optionalThe space behind the dryer is dark.
Refuse bagFor the lint that you remove.
Work glovesThe edge of a metal duct is sharp.

Prepare the dryer

Estimated 1 min

NOTEDisconnect the dryer from the electrical supply first. Every step after this one is safe only while the supply stays disconnected.
  1. Set the dryer to OFF.
    <1m
WARNING

DISCONNECT THE DRYER FROM THE ELECTRICAL SUPPLY BEFORE YOU MOVE IT.
Contact with the supply can give you an electric shock.

  1. Disconnect the dryer from the electrical supply.
    • Remove the plug from the wall outlet.
    <1m
  2. Make sure that the drum of the dryer is empty.
    <1m
  3. Put a refuse bag near the dryer.
    <1m

Clean the lint screen and its housing

Estimated 2 min to 4 min

  1. Remove the lint screen from the dryer.
    <1m
  2. Remove the lint from the lint screen with your hand.
    <1m
  3. Clean the housing of the lint screen with a narrow brush.
    • A pipe cleaner reaches into a narrow housing.
    • Lint collects below the lint screen and stays there.
    2m
  4. Install the lint screen in the dryer.
    <1m

Clean the exhaust duct

Estimated 13 min to 23 min

Exhaust duct cleaning interval
Unverified — do not rely on this value
CONSULT THE MANUFACTURER DOCUMENTATION

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

Three tier-1 manufacturer sources give three different intervals for the same task. Whirlpool (whirlpool-dryer-venting, accessed 2026-07-29) says the venting from the dryer to the outside of the home must be cleaned every one to two years, or sooner if drying performance drops. GE Appliances (ge-dryer-exhaust-duct, accessed 2026-07-29) says to inspect and clean the exhaust ducting at least once a year. Samsung (samsung-dryer-cleaning, accessed 2026-07-29) says to clean the exhaust vent once or twice per year. This page does not average them and does not choose between them. Use the interval in the documentation for your own dryer, and clean it sooner if drying takes longer than it used to.
Exhaust duct material
Manufacturer or standard verified
RIGID METAL DUCT OR CORRUGATED SEMI-RIGID METAL DUCT

Source: Overheated Clothes Dryers Can Cause Fires (CPSC Publication 5022) · tier 1 · accessed 2026-07-29

Exhaust duct diameter
Manufacturer or standard verified
4 in

Source: How to Check Venting — Dryer · tier 1 · accessed 2026-07-29

Maximum length of the exhaust duct
Unverified — do not rely on this value
CONSULT THE MANUFACTURER DOCUMENTATION. THE VENT SYSTEM CHART FOR YOUR MODEL GIVES THE MAXIMUM RUN.

No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.

  1. Find the exhaust duct at the back of the dryer.
    1m
WARNING

IF THE DRYER USES GAS, DO NOT MOVE THE DRYER.
A damaged gas connection can cause an explosion.

  1. Move the dryer away from the wall.
    • Move the dryer only far enough to reach the duct.
    • Do not pull the dryer by the door.
    2m
  2. Release the clamp on the duct at the dryer.
    1m
  3. Disconnect the duct from the dryer.
    <1m
WARNING

REPLACE A PLASTIC DUCT OR A FOIL DUCT WITH A METAL DUCT.
These materials hold more lint and a fire can start.

  1. Examine the material of the duct.
    • Metal duct is the material that most manufacturers give.
    • A plastic duct or a foil duct bends and holds lint.
    <1m
NOTICE

DO NOT USE A SHARP TOOL IN THE DUCT.
A hole in the duct can let lint into the wall space.

  1. Remove the lint from the duct with a long brush.
    • Turn the brush slowly as you move it into the duct.
    • Move the brush along the full length of the duct.
    • Pull the brush out slowly to keep the lint on it.
    4m
  2. Remove the loose lint with a vacuum cleaner.
    2m
  3. Clean the opening of the duct at the back of the dryer.
    1m
  4. Remove the lint from the floor behind the dryer.
    • CPSC tells you to keep the area around the dryer clean.
    2m

Clean the exhaust hood on the outside wall

Estimated 4 min to 5 min

Minimum clearance from the ground to the exhaust hood
Manufacturer or standard verified
305 mm

Source: How to Check Venting — Dryer · tier 1 · accessed 2026-07-29

  1. Go to the exhaust hood on the outside wall.
    1m
  2. Remove the lint from the exhaust hood with your hand.
    • A bird nest or an insect nest also blocks an exhaust hood.
    2m
NOTICE

MAKE SURE THAT THE FLAPS OF THE EXHAUST HOOD MOVE FREELY.
Flaps that do not move keep the lint in the duct.

  1. Make sure that the flaps of the exhaust hood move freely.
    <1m
  2. Make sure that no object blocks the exhaust hood.
    • Plants, snow and stored items block an exhaust hood.
    <1m

Connect the duct before the airflow test

Estimated 6 min

WARNING

DO NOT OPERATE THE DRYER BEFORE YOU CONNECT THE DUCT.
Lint and hot air go into the room and a fire can start.

  1. Connect the duct to the dryer.
    1m
  2. Tighten the clamp on the duct.
    <1m
  3. Move the dryer back to its position.
    • Do not bend the duct as you move the dryer.
    2m
  4. Connect the dryer to the electrical supply.
    <1m
  5. Set the dryer to the air program.
    • The air program uses no heat.
    <1m
  6. Start the dryer.
    <1m
  7. Feel the airflow at the exhaust hood on the outside wall.
    • Strong airflow shows that the duct is clear.
    • Weak airflow shows that a blockage stays in the duct.
    2m
  8. Stop the dryer.
    <1m
  9. Record the date.
    <1m

Terminology

This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.

exhaust duct
Also called: dryer vent, dryer duct, vent pipe, vent hose, exhaust hose, dryer vent pipe, dryer vent tube
lint screen
Also called: lint trap, lint filter, dryer filter, fluff filter, dryer screen, the mesh thing in the door
exhaust hood
Also called: outside vent, vent cap, wall vent, dryer vent flap, outside dryer vent, vent hood
lint
Also called: fluff, dryer fluff, fuzz, dryer dust
clothes dryer
Also called: tumble dryer, dryer machine, drying machine, laundry dryer

When to use a professional

If the dryer uses gas, do not move the dryer. A qualified service person must isolate the gas supply and the electrical supply first.

Stop if you cannot reach the exhaust hood from the ground. Stop if the duct goes into a roof space. Stop if the duct is longer than your brush. A specialist company has the equipment for these ducts.

Stop if the duct has a hole, a crack or a crush. Stop if you find a nest in the duct. Speak to an appliance technician.

CPSC says that a qualified service person must clean the inside of the dryer chassis. Do not open the cabinet of the dryer.

Common questions

How often should I clean my dryer vent?

The three manufacturer sources behind this page give three different answers, so we print all three rather than picking one. Whirlpool says the venting from the dryer to the outside must be cleaned every one to two years, or sooner when drying performance drops. GE Appliances says to inspect and clean the exhaust ducting at least once a year. Samsung says once or twice per year. Use your own manual, and treat a change in drying time as the real trigger regardless of the calendar.

Is a clogged dryer vent actually a fire risk?

Yes, and it is well documented. The U.S. Fire Administration reports that failure to clean was the leading factor contributing to the ignition of home clothes dryer fires from 2018 to 2020, at 31 percent. The CPSC describes the mechanism directly: fires can occur when lint builds up in the dryer or in the exhaust duct, because lint blocks the flow of air, causes excessive heat build-up, and can result in a fire. That is why the duct matters more than the lint trap you already empty.

How do I know if my dryer vent is blocked?

The CPSC gives two signs to watch for. If clothing is still damp at the end of a typical drying cycle, or if drying takes longer than normal, the lint screen or the exhaust duct may be blocked. The third check is to look at the outside vent while the dryer is running: if no exhaust air is escaping, something in the path is blocked.

Is the flexible foil accordion duct behind my dryer a problem?

The CPSC says to replace plastic or foil accordion-type ducting with rigid or corrugated semi-rigid metal duct, and notes that most manufacturers specify metal. The reason is that the flexible plastic and foil types trap lint more easily and are more easily kinked or crushed, which cuts the airflow. If that is what you find when you pull the dryer out, changing it is worth more than cleaning it.

Can I do this myself if I have a gas dryer?

Not the part that involves moving the machine. The connector that feeds a gas dryer is not designed to be dragged around, and damaging it is a serious hazard. Cleaning the lint trap and its housing is fine on any dryer. For anything that requires the dryer to come away from the wall, get a qualified service person to isolate the supplies and move it.

What if my dryer duct runs up into the roof space?

This page does not cover it. A duct that terminates at roof level, runs a long distance, or turns several times needs equipment longer and stiffer than a domestic brush kit, and reaching the outlet is work at height. Hire a duct cleaning service for those, and ask them to report the duct material and length while they are there so you know what you have.

Sources

Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.

  1. Tier 1Overheated Clothes Dryers Can Cause Fires (CPSC Publication 5022)U.S. Consumer Product Safety Commission · accessed 2026-07-29 · re-verification due 2027-01-25
  2. Tier 1Appliance and Electrical Fire SafetyU.S. Fire Administration (Federal Emergency Management Agency) · accessed 2026-07-29 · re-verification due 2027-01-25
  3. Tier 1How to Check Venting — DryerWhirlpool Corporation · accessed 2026-07-29 · re-verification due 2027-01-25
  4. Tier 1Dryer — How to Clean Exhaust / Vent DuctGE Appliances · accessed 2026-07-29 · re-verification due 2027-01-25
  5. Tier 1How to clean your Samsung dryerSamsung Electronics America · accessed 2026-07-29 · re-verification due 2027-01-25

Revision history

Current version 1 · updated 2026-07-29 · next review due 2027-07-29

  1. v1 · 2026-07-29First draft. Hazard spine from CPSC Publication 5022 and the U.S. Fire Administration; procedure detail from Whirlpool, GE Appliances and Samsung service documentation. Cleaning interval and maximum duct length publish as consult-the-manufacturer.

Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.

Comments and corrections

Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.

Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.

The comment system is not connected yet. Comments are stored in GitHub Discussions through Giscus, outside this site, so that a redeploy cannot destroy them.