Upkeep PlanTimed by soil temperature

Dryer vent cleaning: the lint screen is every load, the duct is periodic

Lint is fuel. Most of it gets caught at the screen, but what slips through packs the exhaust duct over months — until the dryer runs hot, runs long, or both.

Two jobs, two schedules

The lint screen is every load — before or after, but every load. The vent and exhaust duct is periodic: CPSC does not pin it to a month, but says to clean it on an interval and watch for the warning signs. Treat spring and fall as reminders, not substitutes for paying attention.

Every load: the lint screen

Pull the screen, peel off the mat of lint, put it back. CPSC's overheated-dryer alert lists this first, and the reason is straightforward: as clothes dry, lint forms and has to go somewhere. The screen is the first choke point.

If clothes are still damp at the end of a typical drying cycle, or if drying suddenly takes longer than it used to, CPSC treats that as a sign the screen or the exhaust duct may be blocked — not as a reason to add another ten minutes on the timer.

Periodically: the vent and exhaust duct

The duct is the path from the back of the dryer to the outside cap. Lint that gets past the screen accumulates there, narrowing the passage until hot, moist air cannot leave at normal volume. CPSC's guidance is to clean the vent and exhaust duct periodically and to verify airflow at the outside vent while the dryer is operating.

Clothes dryer exhaust path: lint screen at the dryer, duct through the wall, outside vent cap — lint buildup in the duct restricts airflow Side view of a clothes dryer connected to a metal exhaust duct that runs through a wall to an outside vent cap. Warm air flows from the drum through the lint screen, into the duct, and out the cap when the path is clear. A second duct segment shows lint narrowing the passage, which traps heat and extends drying time.Dryerlintscreenrigid or semi-rigid metal ductwalloutside ventexhaustescapesBlocked duct: lint narrows the passageAir cannot leave at normal volume. Heat builds, drying takes longer, and the CPSC lists this as a fire path.lint pluglittle or no exhaust at the capClean screen every load
  • Lint screen — clean before or after every load (CPSC)
  • Exhaust duct — clean periodically; use metal, not foil accordion
  • Outside vent — while the dryer runs, you should feel exhaust air

The outside vent test

With the dryer running, walk to the termination cap. You should see or feel exhaust air. CPSC uses that check as the quick diagnostic: if nothing is coming out, something between the drum and the cap is blocked.

Clearing a blockage may mean disconnecting the exhaust duct from the dryer. CPSC reminds you to reconnect the ducting to both the dryer and the outside vent before you run it again — an easy step to skip when you are reassembling in a laundry closet.

Behind and under the dryer

Lint does not only live in the duct. CPSC says to clean behind the dryer, where it piles up on the floor and against the wall, and to keep the whole area free of clutter so air can move. Pull the unit out carefully — most connectors are short — vacuum what you can reach, and push it back without kinking a metal duct.

Duct material matters

If you still have the white or silver foil accordion hose, CPSC wants it gone. Replace plastic or foil accordion-type duct with rigid or corrugated semi-rigid metal duct. Dryer manufacturers specify metal for maximum airflow; the flexible foil type traps lint more easily, kinks more readily, and crushes when the dryer is pushed back against the wall.

Joints should be secured — clamps or foil tape rated for heat, not screws that poke inward and catch lint. The termination cap should open freely; a screen over the outlet traps lint the same way a dirty filter does.

Inside the dryer chassis

CPSC also recommends having a qualified service person clean the interior of the dryer chassis periodically to limit lint accumulation where you cannot reach from the lint trap alone. That is the line between homeowner maintenance and a technician visit — not because the screen job is optional, but because the inside of the cabinet is not designed for casual disassembly.

Loads with gasoline, oils or stains

CPSC calls out clothes soiled with volatile chemicals — gasoline, cooking oils, cleaning agents, finishing oils and stains. Wash them more than once if you can, use the lowest heat setting, and pick a cycle with a cool-down period at the end. Those residues can ignite in a hot drum even when the vent is clean.

Where to stop and call someone

Screen cleaning, vacuuming behind the unit, and brushing a short, accessible duct you can fully reconnect are reasonable homeowner work. Call a qualified dryer exhaust technician when the duct runs through multiple walls or a roof cap you cannot reach safely, when you smell something burning, when the dryer shuts off mid-cycle and will not restart, or when the outside vent still shows no airflow after you have cleared what you can access. Gas dryers add a fuel line to the equation — if you are not confident disconnecting and reconnecting without stressing the connector, that is not the job to learn on.

Where it lands in the year

Our checklist flags March and September for the duct job — bookends around the seasons when the dryer often runs hardest. Pair it with the other fall house jobs: HVAC filter, gutters, and outdoor faucets.

Questions people actually ask

How often should I clean the dryer lint screen?

Before or after every load. CPSC's safety alert is explicit: clean the lint screen or filter each time you dry clothes. That is separate from cleaning the vent duct, which is a periodic job.

How often should I clean the dryer vent duct?

Periodically — CPSC's wording, not a fixed calendar. Our task list flags spring and fall as good moments to do it, but the real trigger is performance: clothes still damp after a normal cycle, or drying taking longer than it used to.

How do I know the vent is blocked?

While the dryer is running, check the outside vent. CPSC says exhaust air should be escaping. If you do not see or feel it, the vent or duct may be blocked. Damp clothes at the end of a typical cycle is another sign.

Can I use the white foil accordion duct?

CPSC recommends replacing plastic or foil accordion-type material with rigid or corrugated semi-rigid metal duct. Manufacturers specify metal for maximum airflow; the flexible foil type traps lint more easily and kinks more readily.

Is this a DIY job or a pro job?

Cleaning the lint screen and vacuuming behind the dryer are homeowner work. Disconnecting ductwork, cleaning deep inside the chassis, or routing through a long or roof-mounted run is where CPSC points you to a qualified service person — especially if the duct does not vent freely after your attempt.

Sources

General fire-prevention information, not a substitute for your dryer manufacturer's installation instructions or local code.