How to Clean a Dryer Vent (and Why It Matters for Fire Safety)

If your clothes take two cycles to dry, the dryer is probably fine. The vent behind it probably is not. Lint that escapes the screen builds up in the duct, making the dryer run hotter and longer, and lint is highly flammable. Here is how to clean the whole path in about an hour.

Why dryer vents matter

The US Fire Administration (USFA) warns that you are at higher risk of a clothes dryer fire if you do not clean your lint filter and dryer vents, and recommends cleaning the lint filter before and after each cycle and checking that the venting behind the dryer is not damaged, crushed or restricted. A clogged vent also wastes energy: the dryer runs longer to remove the same moisture.

Signs your vent is clogged

• Clothes take longer than usual to dry, or come out hot and damp.
• The outside of the dryer or the laundry room gets unusually hot.
• A burning smell when the dryer runs.
• The flap on the outdoor vent hood barely opens while the dryer runs.
• Lint around the lint screen opening or outside the vent hood.

What you need

• Dryer vent cleaning brush kit (flexible rods that connect, with a brush head; some attach to a drill)
• Vacuum with a hose attachment
• Screwdriver and nut driver
• Foil tape (not cloth duct tape) and replacement clamps if needed
• Gloves and a dust mask

Step 1: Clean the lint screen and trap

Remove the lint screen and clean it. Every few months, wash it with warm soapy water and a soft brush: dryer sheets can leave a film that blocks airflow. Hold it under running water; if water pools on top, it needs washing. Vacuum the lint trap housing with a narrow attachment.

Step 2: Disconnect the dryer

1. Unplug an electric dryer. For a gas dryer, turn off the gas valve and be careful not to strain the gas line; if unsure, have a professional move it.
2. Pull the dryer out from the wall carefully.
3. Loosen the clamp and pull the duct off the back of the dryer.

Step 3: Clean the duct

1. Vacuum lint from the dryer's exhaust outlet and the duct opening.
2. Insert the brush into the duct and push it through toward the outside, rotating as you go (clockwise if using a drill, so rods do not unscrew).
3. Work in sections, pulling out lint frequently.
4. Go outside and clean from the exterior hood inward as well.

Step 4: Clean the exterior vent hood

Remove any lint, bird nests or debris from the flap. Make sure the flap opens freely and closes when the dryer is off. Never put a screen over a dryer vent outlet; lint clogs it quickly.

Step 5: Check and reconnect the duct

• Dryer manufacturers generally recommend rigid or semi-rigid metal ducting. Replace plastic or vinyl foil accordion ducts, which can sag, trap lint and are a fire risk.
• Keep the duct as short and straight as possible; every bend adds resistance.
• Join sections with foil tape and clamps; do not use screws that protrude inside and catch lint.
• Push the dryer back without crushing the duct.

Step 6: Test

Run the dryer on air-only or a timed cycle and check outside that air is blowing strongly from the vent hood.

Dryer vent checklist

• Lint screen cleaned (and washed if film present)
• Lint trap housing vacuumed
• Dryer unplugged / gas off
• Duct disconnected and brushed end to end
• Exterior hood cleaned; flap moves freely
• Plastic/foil accordion duct replaced with metal
• Reconnected with clamps and foil tape
• Strong airflow outside confirmed

How often?

Clean the lint screen every load. Brush the vent at least once a year, more often with heavy use, long duct runs or if you notice longer drying times. Mark it on the calendar alongside testing smoke alarms.

Everyday safety habits

• Do not run the dryer when you are leaving home or going to bed.
• Keep the area around the dryer clear of boxes, laundry and cleaning products.
• Do not dry items stained with flammable substances like gasoline or cooking oil without following washing guidance; such stains can ignite.
• Have gas dryers inspected by a qualified professional to check for leaks.

When to call a professional

Long duct runs, roof vents, ducts through finished walls, or vents you cannot reach safely are worth a professional dryer vent cleaning. They can also inspect for crushed or disconnected ducts inside walls.

Apartments and stacked units

In shared buildings, dryer ducts may run through walls to a common exhaust. Clean what you can reach and report weak airflow to building management rather than opening walls.

Inside the dryer cabinet

Lint also collects inside the dryer itself, around the heating element or gas burner and blower housing. Cleaning inside requires removing panels and is model-specific. Consult the manual, and for gas dryers consider having a qualified technician do it. A narrow lint-trap brush and vacuum attachment can safely reach some lint below the screen slot without disassembly.

Lint buildup and energy use

When airflow is restricted, moist air cannot leave quickly, so cycles run longer. Moisture-sensing dryers may keep running until they detect dry clothes, burning extra electricity or gas every load. A clean, short, straight vent is one of the simplest ways to make an existing dryer more efficient, and it reduces wear on the heating element and thermal fuses.

Common mistakes

• Using cloth duct tape, which dries out and fails with heat; use foil tape.
• Leaving a long, crushed transition duct behind the dryer.
• Venting into an attic, crawl space or garage instead of fully outdoors.
• Putting a screen on the exterior hood.