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How To Wash
By Launderwise
12 min read

How to Clean a Dryer Vent (and Prevent a Dryer Fire)

Lint in the dryer duct is highly flammable. Clean the lint screen every load and the full vent once a year — here's the safe step-by-step, signs and tools.

Updated on Reviewed by the Launderwise editorial team Part of our drying and ironing guide
Editorial standards
A pulled-out clothes dryer with its exhaust duct disconnected and a dryer-vent brush clearing lint from the ducting

Disclosure: Some product links are affiliate links; we may earn a commission if you buy through them.

Protocol

Method steps

  1. Unplug the dryer, or shut off the gasFor an electric dryer, unplug it from the wall. For a gas dryer, close the gas supply valve before you move it. This is the step you don't skip — moving a live or gas-connected dryer is how people get hurt.
  2. Pull the dryer out from the wallEase the dryer forward about 30–45 cm (a foot or so) to reach the duct, ideally with a second person, and take care not to crush or kink the flexible transition hose behind it.
  3. Disconnect the duct at both endsLoosen the clamp or peel the foil tape where the duct meets the back of the dryer, and again where it meets the wall outlet. Note how it goes together so you can reconnect it the same way.
  4. Brush and vacuum the duct from both endsFeed a dryer-vent brush through the ducting and work it back and forth with a rotating motion, following the bends, then vacuum out the loosened lint. Do this from the dryer end and the wall/exterior end so the whole run is clear.
  5. Clean the exterior vent hood and check the flapOutside, remove or open the vent cover, pull out the matted lint, and clear any bird or rodent nest. Make sure the flap moves freely — a stuck flap both traps lint and signals a blockage.
  6. Clean the lint-trap slot and housingPull the lint screen, remove the lint by hand, and vacuum down inside the slot where lint also collects. If the screen feels filmy, wash it with a little dish soap and water to clear fabric-softener residue, then dry it before refitting.
  7. Reconnect, restore power or gas, and verify airflowRefit the duct securely at both ends with a clamp or foil tape (not sheet-metal screws, which snag lint), restore power or reopen the gas, then run the dryer and go outside to confirm strong, warm airflow at the exterior vent. Weak airflow means it's still partly blocked.

Clean the lint screen every load and the whole exhaust duct at least once a year — more with pets or a long run. Lint is highly flammable, and failure to clean lint is a leading contributing factor in home dryer fires (NFPA). Unplug (or shut off the gas), brush and vacuum the duct from both ends, then check for strong airflow outside.

There are two different “lint” jobs, and people only ever do the first. The lint screen you pull out between loads catches most of it — but a fine layer still escapes into the exhaust duct that carries hot, moist air outside, and that’s the layer that matters. Lint is highly flammable, and as it builds up in the duct it chokes the airflow, the dryer overheats, and the trapped lint can ignite (CPSC (external link)). Failure to clean lint is a leading contributing factor in home clothes-dryer fires (NFPA (external link)). Clearing the duct at least once a year is the core maintenance step.

Why a clogged dryer vent is a fire hazard

The mechanism is simple and worth understanding, because it’s also why a clogged vent makes drying slower. Lint that gets past the screen settles in the duct and restricts airflow; the dryer can’t push its hot, moist air out, so heat builds up, and the highly combustible lint sitting in that hot duct can catch fire (CPSC (external link)). A restricted airway also makes the dryer work harder and run longer — keeping the lint filter and airway clear helps it run efficiently (ENERGY STAR (external link)).

It also speeds up drying

A clogged vent doesn’t just risk a fire — it makes every load take longer, because the dryer runs extra cycles trying to shift damp air it can’t push out. If your washing suddenly needs two cycles to dry, a blocked vent is one of the first things to check.

Signs your dryer vent is clogged

Catch it early — these are the symptoms to act on (CPSC; U.S. Fire Administration):

  • Clothes take much longer to dry, need a second cycle, or come out very hot.
  • The dryer or laundry room feels hot during a cycle.
  • A burning or musty smell while it runs.
  • Lint piling up around the lint-trap slot or on the floor behind the dryer.
  • The flap on the outside vent doesn’t open (or barely opens) when the dryer runs.

If you ever smell burning, stop the dryer and don’t run it again until the vent is clear. Towels and bedding are the heaviest, lintiest, slowest-drying loads, so they show a developing clog first — see how to keep towels soft and fluffy. And if the dryer runs but won’t heat at all, that’s a different diagnosis than a clog: follow the dryer not heating guide before cleaning anything.

Can you clean it yourself?

Use access and risk, not confidence, to decide. The job is easy when the duct is short and reachable; it stops being a good DIY job when you cannot verify the whole run.

SituationBest routeWhyStop rule
Short, straight duct to an exterior wallDIY full cleanYou can brush/vacuum from both ends and verify airflowStop if airflow is still weak after cleaning
Long duct with several bendsProfessional cleanBrush rods may not reach or may compact lint in bendsDo not force rods through tight turns
Roof or upstairs wall ventProfessional cleanAccess and fall risk matter more than the brush kitDo not climb or work from a roof without proper equipment
Gas dryer you are not comfortable movingProfessional move/cleanThe gas connection changes the riskIf you smell gas, leave and call the utility
Plastic or foil accordion ductReplace with rigid or semi-rigid metalIt kinks, traps lint and is discouraged by safety authoritiesDo not reuse damaged or crushed ducting
Nest, pest debris or repeated clogProfessional inspectionThe blockage may be beyond the visible hoodClean once, then investigate if it returns quickly

The final check is non-negotiable: after reconnecting the dryer, run it and go outside. The exterior flap should open and the airflow should feel strong and warm. If it is weak, noisy or pulsing, the duct is still restricted somewhere. Do not keep running test cycles to “push it through”; stop and clear the run.

Airflow check: what “clean enough” looks like

A dryer vent is not clean just because a brush came back with lint on it. The pass/fail test is airflow at the exterior hood while the dryer runs.

What you see outsideWhat it meansNext action
Flap opens fully and airflow feels strongThe run is likely clearRecheck after the next heavy towel or bedding load
Flap barely opensPartial restriction, stuck flap or crushed transition hoseStop, inspect the hood and the hose behind the dryer
Airflow pulses or sounds blockedLint may be compacted in a bendBrush from both ends again, then call a pro if unchanged
No airflow, dryer heats upSerious blockage or disconnected ductStop using the dryer until the run is cleared
Exterior hood is packed with lint again soonNest, long run, crushed duct or poor terminationHave the full run inspected

This check is also a good way to catch installation problems. A crushed flexible hose behind the dryer can mimic a dirty duct; so can a flap painted shut, a pest screen clogged with lint, or a run that is simply too long and bendy for a DIY brush kit to clear. If the symptoms come back quickly after a full clean, treat it as a duct-design problem rather than a reminder to buy a stronger brush.

How often to clean it

WhatHow oftenSource
Lint screenEvery load, before or afterU.S. Fire Administration
Full vent / exhaust ductAt least once a yearConsumer Reports; NPS
Pets, heavy laundry, or a long/winding ductMore often than yearly
Manufacturer minimumAt least every two yearsMaytag

Lead with the annual clean: it’s the safety consensus across fire and consumer authorities, even though some manufacturers quote a two-year minimum. And whenever the warning signs above appear, clean it then — don’t wait for the calendar.

Loads that expose a weak vent first

If you are unsure whether the vent is borderline, watch the heaviest loads. A clear dryer vent can usually move enough air for towels, jeans and bedding; a restricted one struggles there first. If a normal shirt load dries fine but bath towels suddenly need a second cycle, the duct may be partly blocked even though the machine still “works.” The same applies after moving house, remodeling, or replacing a dryer: a new machine cannot overcome a crushed hose, a long hidden run, or an exterior hood packed with lint. Treat the first slow heavy load as an inspection trigger, not as a reason to run longer cycles.

What you’ll need

This is mostly a brush, a vacuum and a screwdriver. No specialist product is required; an inexpensive dryer-vent brush kit reaches the full run.

Use a proper foil tape made for duct joints or a vent clamp when you reconnect the duct. Do not patch crushed plastic or foil accordion ducting; replace that run with rigid or semi-rigid metal.

A dryer-vent brush kit — flexible rods with a brush head, long enough for your duct run

A shop vacuum with a hose and nozzle

A screwdriver or nut driver — to release the duct clamps

Foil tape or a vent clamp — to reconnect the duct (never sheet-metal screws)

Gloves and a dust mask — lint is fine and messy

How to clean a dryer vent, step by step

  1. 1

    Unplug, or shut off the gas

  2. 2

    Disconnect the duct at both ends

  3. 3

    Brush and vacuum from both ends

    Follow the bends

  4. 4

    Reconnect, then verify airflow outside

    Weak flow = still blocked

The full route in four moves — each is detailed in the numbered steps below.

1. Unplug the dryer, or shut off the gas

For an electric dryer, unplug it. For a gas dryer, close the gas supply valve before you move it. Don’t skip this — moving a live or gas-connected appliance is how people get hurt.

2. Pull the dryer out from the wall

Ease it forward about 30–45 cm (a foot or so) to reach the duct, ideally with a second person, taking care not to crush or kink the flexible transition hose behind it.

3. Disconnect the duct at both ends

Loosen the clamp or peel the foil tape where the duct meets the back of the dryer, and again at the wall outlet. Note how it fits together so you can reconnect it the same way.

4. Brush and vacuum the duct from both ends

Feed the dryer-vent brush through the duct, working it back and forth with a rotating motion and following the bends, then vacuum out the loosened lint. Do it from the dryer end and the wall/exterior end so you cover the run from both directions.

5. Clean the exterior vent hood and check the flap

Outside, open or remove the vent cover, pull out the matted lint, and clear any bird or rodent nest. Confirm the flap moves freely — a stuck flap traps lint and signals a blockage.

6. Clean the lint-trap slot and housing

Pull the lint screen, remove lint by hand, and vacuum down inside the slot, where lint also collects. If the screen feels filmy, wash it with a little dish soap and water to clear fabric-softener residue, then dry it before refitting.

7. Reconnect, restore power or gas, and verify airflow

Refit the duct securely at both ends with a clamp or foil tape rather than sheet-metal screws, which snag lint (Consumer Reports (external link)), restore power or reopen the gas, then run the dryer and go outside to confirm strong, warm airflow at the exterior vent. Weak airflow means it’s still partly blocked (CPSC (external link)).

When to call a professional

A short, straight, ground-floor duct is a reasonable DIY job. Call a professional when:

  • the duct is long or has several bends, or runs up to a roof or through an upstairs wall a brush can’t reach;
  • it’s blocked by a nest or clogs again soon after cleaning;
  • there’s gas-line work you’re not comfortable doing; or
  • you ever smell gas — leave first, then call your utility.

Professional cleaning costs vary widely by region and duct length, so get a couple of local quotes rather than trusting a single figure.

  • Lint is highly flammable. Never run the dryer without its lint filter in place, and never let lint build up in the duct — clean the screen every load (U.S. Fire Administration) and the duct at least yearly (Consumer Reports; National Park Service).
  • Don't vent a dryer indoors — into the house, attic or crawlspace. Vent it outside, and replace flimsy plastic or foil accordion ducting with rigid or semi-rigid metal, which traps less lint and won't kink (CPSC; Consumer Reports). Keep the outside termination clear.
  • Gas dryers: shut off the gas before moving the dryer, and don't strain the gas line. If you ever smell gas, leave the area and call your gas utility or a licensed professional from outside — do not operate the dryer.
  • Take care with clothes soiled with petrol, cooking oil or cleaning solvents — the residue can heat up and ignite in a dryer. Wash such items more than once and hang-dry them if you can, or tumble on low heat with a cool-down cycle, and never leave a pile of oil-stained laundry sitting in or near the dryer (CPSC).

The honest bottom line

Cleaning a dryer vent is a once-a-year job that takes an hour or two and reduces a hidden fire risk many people miss. Do the two-part clean — the screen every load, the full duct yearly — keep the ducting metal and the outside flap clear, and hand the long, roofed or gas-connected runs to a professional. The payoff is a safer setup and, when airflow was the bottleneck, shorter drying cycles.

For the washer side of laundry-appliance care, see how to clean a smelly washing machine; and for why a struggling dryer drags out drying times, the laundry temperature guide.

FAQ

Can a clogged dryer vent cause a fire?

Yes. Lint is highly flammable, and when it builds up in the lint screen and especially the exhaust duct it restricts the airflow the dryer needs to push hot, moist air outside; the dryer then overheats, and the trapped lint can ignite (CPSC). Failure to clean lint is a leading contributing factor in home clothes-dryer fires (NFPA), which is why clearing the duct — not just the screen — matters so much.

How often should you clean a dryer vent?

Clean the lint screen before or after every load (U.S. Fire Administration), and have the whole vent and exhaust duct cleaned at least once a year (Consumer Reports; National Park Service). Clean it more often if you have pets, do a lot of laundry, or have a long or winding duct run. Maytag states a minimum of at least every two years, but once a year is the safer cadence — and any time you notice the warning signs below, clean it then rather than waiting.

What are the signs your dryer vent needs cleaning?

The clearest sign is drying performance: clothes take much longer to dry, need a second cycle, or come out unusually hot. Others include the dryer or laundry room feeling hot, a burning or musty smell, lint piling up around the lint-trap slot or behind the dryer, and the flap on the outside vent not opening when the dryer runs (CPSC; U.S. Fire Administration). Any of these means it's time to clean the vent — and to stop using the dryer until you have if you smell burning.

How do you clean a dryer vent without moving the dryer?

You can do a lot from the outside: open or remove the exterior vent hood and run a dryer-vent brush kit and a vacuum up the duct from that end, which clears the most common buildup near the termination. But the section right behind the dryer and the transition hose are where lint concentrates most, so a thorough clean still means pulling the dryer out and disconnecting the duct at both ends at least once a year. Exterior-only cleaning is a useful top-up between full cleans, not a replacement.

How do you clean a dryer vent on a gas dryer?

The cleaning steps are the same, but the gas connection raises the stakes. Shut off the gas supply valve before you move the dryer, and be careful not to strain or disturb the gas line. When you reconnect, if you ever smell gas, stop, leave the area, and call your gas utility or a licensed professional from outside — don't operate the dryer. If you're not confident working around the gas connection, have a professional do the move and the cleaning.

Should you clean a dryer vent yourself or hire a professional, and what does it cost?

A straight, short, ground-floor duct is a reasonable DIY job with a brush kit and a vacuum. Call a professional when the run is long, has several bends, goes up to a roof or through an upstairs wall, is blocked by a nest, clogs again soon after cleaning, or involves gas-line work you're not comfortable with. Professional cleaning costs vary by region and duct length, so get a couple of local quotes rather than relying on a single figure.

Independent editorial note

Launderwise is an independent laundry and fabric-care publication. We compare products and methods by evidence, practical fit and reader value, and we call out the trade-offs before recommending a route.