Lint builds up where you can’t see it, and a dryer that can’t vent properly runs hotter and longer. A little routine cleaning keeps air moving.
The essentials
- Failure to clean was the leading factor in home clothes dryer fires in U.S. Fire Administration data for 2018 to 2020.
- Clean the lint filter before or after every load, and never run the dryer without it.
- Use rigid or flexible metal duct rather than plastic or foil, and keep it as short and straight as the installation allows.
- Clean lint out of the vent pipe regularly, at least once a year, and sooner if clothes take longer to dry.
- Make sure the outdoor vent flap opens when the dryer runs and isn’t blocked by lint, nests or snow.
Every load of laundry leaves lint behind. Most of it lands on the lint screen, but some escapes into the duct behind the dryer and the vent that carries hot, moist air outside. Over time that buildup restricts airflow, makes the dryer run hotter and longer, and adds fuel close to a heat source.
Why it matters
The U.S. Fire Administration reports that failure to clean was the leading factor in home clothes dryer fires from 2018 to 2020, accounting for 31% of them. Much of that risk is easy to reduce with routine cleaning.
Every load: the lint filter
The National Fire Protection Association’s dryer safety tips are clear:
- Clean the lint filter before or after each load.
- Don’t use the dryer without a lint filter in place.
If you use dryer sheets, some manufacturers suggest washing the screen occasionally with warm soapy water to remove residue that can block airflow. Let it dry completely before putting it back, and check your manual.
Check the duct
Pull the dryer out carefully and look at the duct that connects it to the wall.
- Material: fire safety guidance favors rigid or flexible metal duct. Plastic and foil flexible ducts can sag, crush and trap lint.
- Condition: look for kinks, crushed sections and loose joints.
- Length and route: shorter, straighter runs move air better. Your dryer’s installation instructions list the maximum length and the duct types it allows.
How to clean the vent pipe
NFPA’s tip sheet recommends cleaning lint out of the vent pipe at least once a year, and sooner if clothes are taking longer to dry.
- Disconnect the power. Unplug an electric dryer. For a gas dryer, see the warning below.
- Move the dryer out far enough to reach the duct without straining it.
- Detach the duct from the dryer and the wall by loosening the clamps.
- Vacuum lint from the dryer’s exhaust opening and from both ends of the duct.
- Brush the duct. A dryer vent brush kit with flexible rods reaches into longer runs. Work from inside, from outside, or both.
- Reconnect the duct with clamps or foil tape made for ducts. Avoid screws through the duct, which can catch lint.
- Test. Run the dryer and check outside that air is flowing strongly and the flap opens.
Safety first
Gas dryers are connected to a gas line, and moving them can strain or loosen the connection. If you smell gas, leave the house and call your gas utility or 911 from outside. Have a qualified professional disconnect and reconnect a gas dryer, or hire a dryer vent cleaning service to do the whole job.
Don’t forget the outside vent
The flap on the outside wall should open freely when the dryer runs and close when it stops. Clear away lint, leaves, nests and, in winter, snow. A vent hood that stays shut or blocked traps hot air and lint in the duct.
Pro tip
On a dry day, run the dryer and hold your hand near the outside vent. Weak airflow, even with a clean lint screen, is a strong sign the duct needs attention.
Everyday safety habits
- Don’t leave the dryer running when you go out or go to bed.
- Keep the area around the dryer clear of laundry piles, boxes and cleaning products.
- Have gas dryers checked by a qualified professional, since fuel-burning appliances can also produce carbon monoxide.
- Make sure the laundry area is covered by working smoke alarms. Our guide to smoke and CO alarms explains where they belong.
Dryer vent cleaning is a natural fit for a once-a-year routine. It’s on our fall home maintenance checklist with the other jobs worth doing before winter.
Common questions
How do I know if my dryer vent is clogged?
Warning signs include clothes that take longer than usual to dry, a dryer or laundry room that gets very hot, a burning smell, and an outside flap that barely opens. Stop using the dryer until you’ve checked the vent.
Can I clean the vent myself?
Many homeowners can clean a short, accessible duct with a dryer vent brush kit. Long or hidden runs, rooftop vents and gas dryers are good jobs for a professional dryer vent cleaning service.
Is the foil accordion duct behind my dryer OK?
Plastic and foil flexible ducts can sag, crush and trap lint. Fire safety guidance favors rigid or flexible metal duct, and your dryer’s manual will list the types it allows.
Is it safe to run the dryer overnight or while I’m out?
Fire safety organizations advise against leaving a dryer running when you leave home or go to bed.
This guide is general information, not professional advice. Follow the manufacturer’s instructions and your local building codes, and hire a licensed professional for electrical, gas, structural or roofing work.