How to clean a dryer vent: from the dryer to the outside flap

Step by step: how to clean a dryer vent

Safety first. Unplug an electric dryer before you move it. For a gas dryer, slide it out gently so you do not kink or strain the gas line; if the connector is old, damaged or you smell gas, stop and call a professional, and NFPA advises having gas dryers inspected by a qualified professional. Use a sturdy ladder only for low wall vents; leave roof vents to a pro.

1. 1

   Unplug the dryer and pull it out

   Unplug it and slide it out from the wall far enough to reach the back, with a helper if it is heavy. Protect the floor with a towel. On a gas dryer, move it slowly and keep an eye on the flexible gas connector.

2. 2

   Disconnect the transition duct

   Loosen the clamp at the back of the dryer and pull the short duct off, then do the same where it meets the wall. Expect a handful of lint to fall out. Carry the duct outside and shake or brush it clean, or replace it if it is crushed, torn, plastic or thin foil.

3. 3

   Vacuum the dryer’s exhaust port

   Vacuum lint out of the round exhaust outlet on the back of the dryer as far as the crevice tool reaches. Also vacuum the floor and wall behind the dryer, which the USFA flags as a place lint builds up.

4. 4

   Brush the wall duct from inside

   Attach the brush head to two or three rods and feed it into the wall opening, adding rods as you go. If you use a drill, run it slowly and always clockwise so the rods do not unscrew inside the duct. Pull the brush back every few feet and vacuum the lint it drags out.

5. 5

   Clean the outdoor vent hood

   Go outside, open or remove the vent cover, and pull out any lint, nests or debris by hand. Brush the duct from this end too until the brush comes out mostly clean. Make sure the flap or louvers swing freely and that there is no screen trapping lint.

6. 6

   Clean the lint filter and its slot

   Pull the lint screen, clear it, and wash it with warm soapy water if it looks waxy. Vacuum down into the lint filter slot with a long, thin lint brush or vacuum attachment.

7. 7

   Reconnect with metal duct and foil tape

   Fit the transition duct to the wall and the dryer, tighten the clamps and seal the joints with aluminum foil tape. Keep it as short and straight as you can, with no crushed sections when you push the dryer back.

8. 8

   Test the airflow

   Plug the dryer in and run it on air fluff or a heated cycle for a few minutes. Outside, the flap should open and you should feel a strong, warm flow. A weak trickle means there is still a blockage or a crushed duct.

Signs your dryer vent needs cleaning now

Clean the vent right away if a normal load takes noticeably longer to dry, the dryer or laundry room feels unusually hot, or you smell something hot or burning. Lint in a vent restricts airflow, which makes the dryer run hotter and longer.

• Clothes come out damp or hot after a full cycle.
• The outdoor flap does not open when the dryer is running, or you see lint around it outside.
• The top of the dryer is hot to the touch.
• Lint collects behind the dryer or around the lint screen slot.
• It has been more than a year since the last cleaning.

This is a fire safety job, not just a maintenance one. The U.S. Fire Administration reports that failure to clean (31%) was the leading factor contributing to the ignition of home clothes dryer fires from 2018 to 2020.

How often should you clean a dryer vent?

Clean the vent duct at least once a year, and the lint filter before or after every load. NFPA’s dryer safety tips say to clean lint out of the vent pipe once a year, or more often if drying takes longer than normal, or to have a dryer lint removal service do it.

Plan on more often if any of these apply:

• A large household doing several loads a day.
• Pets, lots of towels or fleece, which shed more lint.
• A long duct run, many bends, or a vent that exits through the roof.
• Regular use of dryer sheets. ENERGY STAR notes they can leave a film on the lint filter that cuts airflow, and suggests scrubbing the filter with a toothbrush once a month.

Which dryer duct is safe?

Use rigid or semi-rigid metal duct. NFPA recommends rigid or flexible metal venting to keep airflow up and drying time down, and the white vinyl or thin foil accordion ducts many older homes still have crush easily and trap lint in their ridges.

Join sections with foil tape and clamps rather than screws, which poke into the duct and snag lint. Your dryer’s installation instructions list the maximum duct length and number of bends for your model.

When to hire a dryer vent cleaning service

Call a professional if the vent exits through the roof, the run is long or hidden in a ceiling, you cannot get airflow back after brushing, or you have a gas dryer with an old connector. Those cases need ladders, inspection cameras or gas work.

The USFA also advises having your dryer installed and serviced by a professional and checking that the venting behind it is not damaged, crushed or restricted. While the dryer is pulled out, it is a good time to clean the cabinet and drum too; see our dryer cleaning guide.

Mistakes to avoid

• Cleaning the lint screen but never the duct, which is where the dangerous buildup collects.
• Spinning the brush rods counterclockwise with a drill, which unscrews them and leaves a rod stuck in the wall.
• Putting back a crushed, kinked or plastic transition duct.
• Sealing joints with cloth duct tape, which dries out and peels off in the heat.
• Pushing the dryer tight against the wall so the duct folds flat behind it.
• Forgetting the outdoor hood, where lint and bird nests block the flap.