How To Clean a Dryer Vent Safely

To clean a dryer vent, unplug the dryer first (and shut the gas valve on a gas dryer). Pull the machine straight out without crushing the duct behind it, then disconnect the transition duct from the exhaust port. Vacuum lint at both ends, run a dryer-vent brush through the run to the exterior flap, and clear the outdoor hood. Reconnect with a clamp, then slide the dryer back so the duct stays open — a crushed vent is how lint and heat pile up. Clean the lint screen after every load. Do the duct at least once a year. Lint in a hot, restricted exhaust is a fire.

Safety first

• Unplug it. Electric dryers are 240 volts. Do not work behind a live machine. On a gas dryer, unplug the 120-volt cord and close the gas shutoff. If you are not sure which valve that is, or the flex gas line has to move, stop and hire someone — a disturbed gas connection is a carbon-monoxide and fire problem, not a cleaning tip.
• Do not crush the vent. The most common DIY mistake is shoving the dryer back so the flexible duct kinks or pancakes against the wall. A crushed 4-inch duct becomes a 2-inch heater. Leave slack that is short and smooth, not a coiled extra loop, and check from the side that the run is round before you call it done.
• Lint is the fuel. NFPA’s Home Dryer Fires report (2014–2018 annual averages) estimated about 13,820 U.S. home structure fires a year involving a dryer, with failure to clean the leading factor (about a third of those fires). Dust, fiber, or lint was the first thing ignited in about 27%. This is not a “maybe someday” chore.
• No vinyl, no thin foil accordion as the house run. Building codes (IRC dryer exhaust) want smooth rigid metal in the wall. A short listed transition duct (UL 2158A, generally 8 feet max, not hidden in the wall) is what connects the dryer to that run. White plastic dryer hose and cheap foil that crushes in your hand are fire hazards. Replace them; do not “clean around” them.
• No screws poking into the duct. They snag lint. Use clamps and listed foil tape on the outside of joints.
• Get off the roof. If the termination is on the roof, a high wall, or you cannot see the whole run, that is a pro job. So is a duct buried in a chase you cannot pull a brush through.

Three different things people call “the vent”

• Lint screen — the mesh in the door or on top. Empty it every load. If you skip one thing, skip something else.
• Transition duct — the short, usually flexible piece from the dryer to the wall. This is what you crush when you shove the machine back.
• The house duct and exterior hood — rigid metal through the wall or floor, ending at a damper flap outside. Screens on that hood catch lint and wildlife; a proper damper flap is what you want, not a mesh that clogs shut.

When to stop and call a pro

Hire a dryer-vent service or an appliance tech — not a general “we’ll try” guess — if any of this is true:

• Gas dryer, and you would have to move or disconnect the gas line
• Roof jack, second-story termination, or a ladder you do not trust
• Long, concealed, or multi-elbow run you cannot push a brush through
• The duct is vinyl, crushed foil, or coming apart in the wall
• Burning smell, scorch marks, tripped thermal fuse, or clothes that still take two cycles after you cleaned the screen
• You drop a brush or rod in the duct and cannot get it back

A cheap kit is fine for a short, visible, electric-dryer run you can see from both ends. It is not a substitute for a camera inspection on a 25-foot concealed line.

What you need (short, accessible run)

• A dryer-vent brush kit: rods that lock together and a brush that fits a 4-inch duct. Tape the rod joints so they cannot unscrew inside the pipe.
• A drill on low speed, or the kit’s hand crank if you do not want a drill in a tight space
• A vacuum (shop vac is better)
• A screwdriver or nut driver for the clamp
• A new listed transition duct and a clamp, if what you find is crushed, vinyl, or torn
• A flashlight, and a second person if the dryer is heavy

We are not ranking Amazon kits. Look for rods that lock, a brush head that matches 4-inch duct, and enough length to reach the exterior from the dryer (or the other way). If the rods feel like they will snap, they will snap in the wall.

Step by step

1. Unplug. Gas valve off if it is gas. Let a just-finished dryer cool. Do not start this mid-cycle.
2. Pull the dryer out in a straight line. Watch the duct. If it is stapled, crushed, or too short to move the machine, stop and fix the duct — do not rip it.
3. Disconnect the transition duct from the dryer outlet. Loosen the clamp. Do not yank. Vacuum the dryer’s exhaust port and the first feet of duct.
4. Brush the run. Feed the brush toward the outside, adding rods as you go, slow drill speed so you are sweeping lint to an opening rather than packing a wad in an elbow. Work from the exterior hood the other direction if you can reach it. Have someone watch the outdoor flap so you know the brush made it through.
5. Clean the exterior hood. Open or unscrew the cap. Pull the lint out. Check for a bird nest. The flap should swing freely. If there is a mesh screen packed with fuzz, that screen is the problem — a solid damper with no screen is the usual replacement.
6. Vacuum the mess so it does not go back in.
7. Reconnect. A clamp beats a wad of tape. Transition duct: listed, as short as will still let you pull the dryer out 18–24 inches later, no extra coils. Not concealed in the wall.
8. Slide the dryer back and look. From the side or with a flashlight, the duct should be round, not folded. Restore gas only if you shut it off and you know the connection did not twist. Plug back in. Run a short empty cycle and confirm air is actually coming out the exterior flap — you should feel exhaust, not a sealed hood.

If you cannot move the dryer

You can sometimes brush from the outdoor hood inward on a short, straight, ground-level termination. That does not clean the lint sitting in the dryer’s own port, and it does nothing if the transition duct is already crushed. It is a stopgap, not the annual job. Do not stand on a steep roof to try it.

The lint screen (every load)

Peel the lint off after every single load. Every few weeks, wash the screen in warm soapy water and let it dry completely before it goes back — dryer-sheet residue films the mesh and chokes airflow even when the screen “looks” clean. Never run the dryer without the screen in place. That is how the duct, and sometimes the cabinet, fills with lint you then cannot see.

How often, and how you know it is overdue

• Lint screen: every load
• Transition duct and accessible run: at least yearly; more often with pets, towels, a big household, or a long duct
• Overdue signs: clothes need two cycles, the cabinet or the laundry feels too hot, a burning or dusty-hot smell, the outdoor flap barely opens, or lint tufts around the hood

Apartments and condos

You still own the lint screen and whatever duct you can see behind the machine. The chase through the building is usually the landlord or HOA. Ask when it was last cleaned rather than assuming the stack is clear. A crushed plastic hose behind a stacked unit is still yours to replace with a listed transition.

What this is not

Pro Housekeepers cleans homes, not dryer duct chases. We will not pretend a house-cleaning visit is a vent-fire inspection. What we can do is the laundry room around the machine — lint on the floor, the cabinet top, the filter you can pull — on a regular cleaning visit. The duct itself is unplug, don’t crush, brush or call a vent pro, and keep the screen clean.

FAQ

Is foil duct OK behind the dryer?
A short, listed UL 2158A transition, installed without kinks, is the usual allowed connector. Cheap vinyl and easily crushed foil used as a long house run are not. Semi-rigid metal is sturdier than foil and still lets you pull the dryer out. Rigid metal belongs in the wall.

How much does a pro charge?
It varies by city, access, and whether they need a roof. Think in terms of a service call, not a $20 kit, and get the price before they climb. DIY is only cheaper if you can actually reach both ends safely.

The dryer still smells hot after I cleaned the screen.
Unplug it and stop using it until the duct is cleared. That smell is the reason this article exists. If you cannot inspect the run, call a vent cleaner or appliance tech the same day.

Can I vent into the garage or crawl space?
No. Moist lint air belongs outside. Indoor venting is a moisture and fire problem, and it is not a workaround for a clogged hood.