How to Clean a Dryer Vent Brush, Hood, Airflow Test

Before you start

Lint goes two places: into the screen you empty every load, and past it into the cabinet and the duct. The National Fire Protection Association advises clearing lint out of the vent pipe once a year, or sooner when drying starts to drag, and says you can do it yourself or have a lint removal service do it. Its report on dryer fires mentions the long, thin brushes sold for the purpose. A kit of flexible rods that spin from a cordless drill, a shop vacuum, a nut driver for the clamps and a flashlight cover most homes.

Unplug an electric dryer before moving it. A gas dryer is a different matter: the flexible gas connector behind it should not be bent hard or pulled loose, and the NFPA recommends having a professional inspect gas dryers to make sure the line and connection are intact and not leaking. If you smell gas at any point, stop, leave the house and call the gas utility from outside.

Step 1: The screen and the floor behind the machine

Pull the lint screen and clean it. Then slide the dryer out and vacuum the floor and the wall behind it. The Consumer Product Safety Commission notes that lint builds up back there too, and recommends having a qualified service person clean the inside of the cabinet from time to time.

Step 2: Take off the transition hose

Loosen the clamp at the back of the dryer and at the wall, and pull the short hose free. Look at it honestly. White vinyl or thin foil accordion hose should go in the trash; the CPSC says that kind of duct traps lint and crushes more easily, and recommends rigid or semi-rigid metal in its place. Florida's residential code allows a single listed transition duct no longer than 8 feet and never hidden inside a wall.

Step 3: Brush the duct

Feed the brush into the wall opening, spin it in the direction that keeps the rod sections tight, and work it out to the far end a section at a time, then back. Pull lint out with the vacuum as it loosens. If the brush meets something solid it will not pass, do not force it: that can be a crushed section, a separated joint inside a wall, or a nest.

Step 4: The outside hood

Go outside and clear the hood by hand, removing lint, grass and leaves. Check that the flap swings freely and closes on its own. Florida's code wants a backdraft damper at the outlet and no screen there, because a screen catches lint; if someone has added one, take it off. Twigs or grass packed into the hood, or chirping inside, are signs of a bird nest. If there may be eggs or chicks, leave it alone and read the bird nest removal page before doing anything.

Step 5: Put it back and test it

Reconnect the hose at both ends with the clamps, without kinks, and push the dryer back without crushing it. The CPSC reminds owners to reconnect the duct to the dryer and the outside vent before running the machine again. Then run a load on high heat and stand at the hood: a strong, warm stream that pushes the flap wide open means the job worked. Don't add screws to the duct joints when reassembling; the code forbids fasteners that poke into the airflow and catch lint.

When this is not a homeowner job

• The vent leaves through the roof. Many single-story Ocala homes with a central laundry run the duct across the attic to a roof cap. The cap has to be opened and cleared from above, and the work needs a ladder and secure footing on a hot, often steep roof. Nearly three in ten Marion County residents are 65 or older, and no clean duct is worth a fall. That job is roof dryer vent cleaning.
• The run is long or the brush will not go through. A long run with several elbows, or a blockage that will not move, is better cleaned from both ends with professional equipment.
• The duct ends under a manufactured home. Federal standards at 24 CFR 3280.708 forbid that termination, so the duct needs extending, not just cleaning.
• The duct is crushed, split or plastic inside a wall. That is dryer vent repair.

What a pro adds

A professional cleaning covers the whole run from the drum to the outlet, opens the roof cap if there is one, and ends with an airflow check. The dryer vent cleaning page explains what that visit covers, and the pricing page shows what operators serving Marion County post for it.