If your dryer used to finish a load in 45 minutes and now crawls past an hour, your vent is probably choked with lint. That’s not just annoying—it’s risky. The U.S. Fire Administration estimates roughly 2,900 home clothes dryer fires each year, and the leading culprit is lint buildup. A clogged vent also forces the dryer to run hotter and longer, wearing out heating elements and cooking your clothes. The good news: with a basic brush kit, a vacuum, and an hour of focused work, you can restore airflow, cut energy use, and lower fire risk. You’ll learn what tools actually help, how to clean the vent line from both ends without making a mess, how to reassemble the duct the right way (no screws poking into the airstream), and how often to repeat the job depending on your home. I’ve done dozens of these cleanings for neighbors and rentals; the difference in airflow is immediate, and the fresh lint you’ll pull out is honestly shocking.
Quick Answer
Unplug the dryer (and shut off gas if applicable), pull it out, disconnect the vent, then use a 4-inch dryer vent brush with extension rods and a vacuum to clear the duct from both the dryer side and the exterior hood. Clean the exterior flap, reassemble with rigid or semi-rigid metal duct sealed with foil tape (not screws or cloth duct tape), then run the dryer on air-only for 5–10 minutes to blow out residual lint and verify strong airflow. Do this at least yearly—every 6 months if you dry often or have pets.
Why This Matters
Dryer lint is tinder. According to national fire data, thousands of home dryer fires occur annually, most starting with lint buildup that overheats. That’s the worst-case scenario. But even before fire risk, a clogged vent quietly wastes money. A typical electric dryer uses 2–6 kWh per load. If your vent is restricted and each load adds 15–20 minutes, you can easily burn an extra 30–40% energy across dozens of loads a month.
There’s more. Tight vents cook fabrics, fray elastic, and turn your laundry room into a sauna. I’ve seen gas dryers with blocked vents backdraft warm, damp exhaust right into the room—exactly what you don’t want with combustion appliances. Real-world clues are surprisingly ordinary: towels still damp after a full cycle, a dryer top that’s too hot to touch, lint dust on the wall behind the machine, or a weak puff of air outside when the dryer runs. A clean vent restores brisk airflow, shortens cycle times, extends appliance life, and meaningfully lowers risk. It’s a small job with a big payoff.
Step-by-Step Guide
Step 1: Prep, power, and tools
Unplug the dryer. For gas units, close the shutoff valve (handle perpendicular to the pipe). Slide the dryer out gently—use furniture sliders if you have them. Don’t kink the gas line or crush the vent. You might find dryer vent cleaning brush helpful.
- Tools: 4-inch dryer vent brush kit with 20–30 ft rods, drill, shop vacuum with crevice tool, screwdriver/nut driver, UL 181 foil HVAC tape, new semi-rigid or rigid metal transition duct (UL 2158A rated), work gloves, mask.
- Avoid: plastic or “slinky” foil ducts and cloth duct tape. They’re a fire and lint hazard.
Step 2: Disconnect and inspect
Loosen the clamp and detach the transition duct from the dryer. If it’s flimsy foil or plastic, plan to replace it. Vacuum lint around the outlet and behind/beneath the dryer. Remove the lint filter and vacuum the lint chute. If you can access the blower intake (behind a service panel on some models), vacuum that carefully—metal edges are sharp.
- Look for crushed sections, screw tips inside the duct, or melted spots. These catch lint and need replacing.
Step 3: Brush the vent line from indoors
Attach the brush to one or two rods and insert into the wall duct. Spin the brush with a drill on low speed clockwise only so the rods don’t unthread. Feed rods one at a time until you reach the exterior cap.
- Tape rod joints so they don’t separate inside the wall.
- Don’t muscle through tight elbows—work the brush in and out to loosen lint.
- If the brush snags, stop, reverse slightly by hand (not drill), and pull back.
Step 4: Finish from the outside
Go outside and remove the vent hood if needed. Clear lint, stuck flaps, and any bird nest material. Clean the last section by brushing inward and vacuuming. The flap should open freely and fully under airflow. If there’s a screen, remove it—screens are lint traps and aren’t allowed on dryer terminations in most codes. You might find dryer vent cleaning kit helpful.
- Pro tip: If the vent exits the roof, prioritize cleaning from the laundry room side and consider a professional for roof access.
Step 5: Reassemble correctly
Use a short, smooth path with rigid or semi-rigid metal. Slide the transition duct onto the dryer and wall stubs, secure with worm-gear clamps, and seal seams with UL 181 foil tape. Don’t use sheet-metal screws that penetrate the duct—they snag lint. Push the dryer back, keeping the duct round and uncrushed. For gas dryers, reopen the valve and check with soapy water at the connection for bubbles (leaks).
Step 6: Test and set a schedule
Run the dryer on air-only for 5–10 minutes. Outside, you should feel strong, warm airflow and see the flap snapping fully open. If airflow is weak, repeat brushing or look for hidden kinks/elbows. Time your next loads; most mixed loads should finish in about 45–60 minutes. Put a reminder on your calendar to clean every 6–12 months (every 3–6 with pets or heavy use). Wash the lint screen with dish soap every couple of months to remove fabric softener residue. You might find dryer lint vacuum attachment helpful.
Expert Insights
The biggest misconception I hear is, “I clean the lint screen, so I’m good.” The screen catches the big stuff. The fine lint sails past and glues itself inside elbows and that first 6–10 feet of duct. A vacuum alone won’t reach it, and a leaf blower can pack lint into a wad at the first elbow or launch it across your yard. Use a rotary brush first; use air only as a follow-up on straight, short runs.
Builders still install flexible foil transition ducts because they’re cheap and easy. They collapse, tear, and trap lint. Swap to UL 2158A-rated semi-rigid or rigid metal and keep it short. Also skip sheet-metal screws in the airstream—foil tape and proper clamps are the right way. If your vent run is long or has multiple elbows, remember the typical maximum equivalent length is around 35 feet minus 5 feet for each 90-degree turn; exceed that and performance drops fast. That’s where booster fans come in, but they require maintenance and proper pressure switches.
Two more pro notes: roof caps clog faster than wall caps because lint sticks to dampers—check them more often. And with gas dryers, poor venting isn’t just slow drying; it’s a carbon monoxide risk. If you smell exhaust or feel heat building in the room, stop and fix the vent path before running another load.
Quick Checklist
- Unplug dryer and close gas shutoff valve (if gas).
- Pull dryer out without crushing the vent or gas line.
- Disconnect and discard flimsy foil/plastic ducting.
- Brush and vacuum the vent line from both ends.
- Clean exterior hood and ensure flap opens fully.
- Reassemble with semi-rigid/rigid metal and foil tape.
- Run air-only test and verify strong exterior airflow.
- Schedule vent cleaning every 6–12 months; wash lint screen periodically.
Recommended Tools
Recommended Tools for how to clean clothes dryer vent
Frequently Asked Questions
How often should I clean a dryer vent?
A good baseline is every 12 months. If you dry multiple loads per day, have long duct runs, multiple elbows, or pets that shed, clean every 3–6 months. Roof terminations and cold climates (condensation) may also require more frequent service. If dry times creep past an hour, move the cleaning up.
Can I just vacuum the vent instead of using a brush kit?
A vacuum helps collect loosened lint, but it won’t scrub the packed layer that forms on the duct wall—especially at elbows. A rotary brush physically breaks that crust so the vacuum or airflow can remove it. Use both: brush the full run, then vacuum from each end for best results.
What are the signs my dryer vent is clogged?
Longer dry times, a hot or humid laundry room, a dryer top that’s unusually warm, a burnt-lint odor, and lint dust behind the machine are common clues. Outside, the vent flap may barely open or you’ll feel weak airflow. You may also see more lint collecting around the door gasket or notice clothes coming out hotter but not fully dry.
Is flexible foil or plastic ducting safe to use?
No. Thin foil and plastic ducts crush easily, trap lint, and can melt or burn. Most manufacturers and codes call for rigid or semi-rigid metal for the transition and the in-wall run. Use UL 2158A-rated transition duct, keep it as short and straight as possible, and avoid screws that penetrate the airstream.
How do I clean a roof-vented dryer safely?
Roof vents are tricky and risky to access. Clean thoroughly from the laundry room side with a brush kit, then inspect the roof cap visually from the ground if possible. If you must go up, use proper fall protection and a spotter. Many roof caps have backdraft dampers that stick; clearing and lubricating the hinge may require professional access.
What special precautions are needed for gas dryers?
Shut off the gas before moving the dryer and avoid stressing the flexible gas connector. After reassembly, reopen the valve and check connections with soapy water—bubbles indicate a leak. Poor venting on gas dryers can lead to carbon monoxide concerns, so never operate a gas dryer with a known vent restriction.
Are dryer sheets and fabric softener affecting my vent or lint screen?
Dryer sheets can leave a film on the lint screen that reduces airflow. Every couple of months, wash the screen with warm water and dish soap, dry it, and reinstall. It doesn’t gunk up the vent itself much, but the reduced screen airflow can trick the dryer into longer cycles, compounding lint buildup down the line.
Conclusion
A clean dryer vent is one of those unglamorous chores that pays back immediately: faster loads, lower bills, and a safer home. Unplug the unit, brush the entire run from both ends, rebuild the transition with proper metal duct and foil tape, and confirm strong outdoor airflow. If your run is long or goes to the roof, consider a pro once a year and do interim touch-ups yourself. Put a reminder on the calendar, and enjoy getting your laundry done in less time without the hot, musty laundry room.
Related: For comprehensive information about Ventisafe, visit our main guide.