Guides · Safety
How often to clean a dryer vent, and how to do it yourself
Clean the lint screen after every load and the whole dryer vent at least once a year. Lint that slips past the screen builds up in the duct, slows drying and is the leading factor in home dryer fires. Cleaning a short vent yourself takes about an hour and a brush kit from the hardware store.
How to clean a dryer vent
- 01
Unplug the dryer and close the gas
Unplug it or switch off its breaker. On a gas dryer, close the shutoff valve on the gas line first and move the machine gently so the flexible gas connector is not kinked.
- 02
Pull the dryer out and disconnect the duct
Slide it out far enough to reach behind it, loosen the clamp and pull the short transition duct off the dryer outlet.
- 03
Brush the duct toward the outside
Feed a dryer vent brush (a round brush on flexible rods) into the duct and turn it as you push toward the outside wall. Pull it back, empty the lint and repeat until it comes out clean.
- 04
Clear the outside hood
Outside, pull the lint out of the vent hood and check that the flap or louvers open and close freely. Take off any screen over the outlet; a screen catches lint.
- 05
Vacuum the dryer end
Vacuum the dryer outlet, the lint screen slot and the floor behind and under the machine.
- 06
Reconnect and test
Reattach the duct with its clamp, push the dryer back without crushing the duct, then run it and check outside that the flap opens and the air flows strongly.
How often to clean each part
| Part | How often | Why |
|---|---|---|
| Lint screen | Every load | The CPSC says clean it before or after each load. |
| Whole vent duct to the outside | At least once a year | More often if drying takes longer than it used to, the run is long or has bends, or you run many loads. |
| Behind and under the dryer | Every few months | Lint collects on the floor and around the back of the machine. |
| Inside the dryer cabinet | Every few years, by a service tech | The CPSC recommends having a qualified person clean the chassis periodically. |
| Plastic or foil accordion duct | Replace it now | It traps lint and crushes easily; the CPSC calls for rigid or semi rigid metal duct. |
From the U.S. Consumer Product Safety Commission and the NFPA clothes dryer safety tips, linked below.
Why it matters
Failure to clean was the leading factor in home clothes dryer fires in the U.S. from 2018 to 2020, at 31 percent, according to the U.S. Fire Administration. Lint is fine, dry and burns easily. When the duct narrows, the dryer runs hotter and longer, and the lint sits right in the path of that heat.
A clogged vent costs you on every load too. The dryer runs longer to do the same job, and a dryer that runs hot wears out its heating element and thermal fuse sooner.
Signs your dryer vent is clogged
- A normal load needs a second cycle, or clothes are still damp at the end. The CPSC names this as the sign of a blocked screen or duct.
- The top of the dryer, or the clothes, feel hotter than usual.
- A burning smell when the dryer runs, or a musty, damp laundry room.
- The flap on the outside vent barely opens while the dryer is running.
- Lint around the outside hood or on the siding below it.
- You cannot remember the last time the vent was cleaned.
Do it yourself or hire a pro
A short, straight duct that goes out through a wall near the dryer is a do it yourself job: about an hour with a brush kit and a vacuum.
Call a dryer vent cleaning service when the duct runs through the attic or ends on the roof, when it is long or has several bends, when birds have nested in the hood, or when you clean it and drying is still slow. A pro brings rotary brushes and an air whip and can measure the airflow at the hood. In Massachusetts, Handy Circle sends the job to vetted local pros who quote it.
The duct rules that keep a vent clear
- Use rigid or semi rigid metal duct, 4 inches across. Plastic and foil accordion duct traps lint and crushes behind the machine.
- Keep it short. The model code and InterNACHI give 35 feet as the usual limit for a rigid metal duct, minus 5 feet for each 90 degree elbow and 2.5 feet for each 45 degree bend, unless the dryer maker allows more.
- Join sections with clamps or foil tape rather than screws that poke into the duct and catch lint.
- End it outside, at a hood with a flap and no screen. Never let a dryer vent into the attic, a crawl space or a wall cavity.
- Keep the transition duct behind the dryer short and free of kinks.
Keep the date
Once a year is exactly the kind of job that slips. Write the date in your home maintenance log, and see the other yearly safety jobs in how often to replace smoke detectors and the home maintenance schedule.
Questions
How often should a dryer vent be cleaned?
Clean the whole vent duct at least once a year and the lint screen after every load. Clean the vent sooner if drying starts taking longer, the duct is long or has bends, or you run many loads a week.
Can I clean my dryer vent myself?
Yes, when the duct is short and goes out through a nearby wall. A dryer vent brush kit and a vacuum do it in about an hour. Hire a pro for long runs, roof vents or a duct you cannot reach.
What are the signs of a clogged dryer vent?
Loads that need a second cycle, clothes or the dryer running hot, a burning smell, lint around the outside hood and a vent flap that barely opens while the dryer runs.
Is cleaning the lint screen enough?
No. The screen catches most lint, but some passes it and builds up in the duct over months. The duct needs its own cleaning.
What type of dryer duct is safest?
Rigid or semi rigid metal duct, 4 inches across. The CPSC recommends replacing plastic or foil accordion duct, which traps lint and crushes easily.
Sources
- U.S. Fire Administration: appliance and electrical fire safety (failure to clean, 31 percent of home dryer fires, 2018 to 2020)
- U.S. Consumer Product Safety Commission: overheated clothes dryers can cause fires (Publication 5022)
- NFPA clothes dryer safety tip sheet
- NFPA dryer safety tips as published by the Chimney Safety Institute of America (clean the vent once a year or more often)
- InterNACHI: inspecting the dryer exhaust (4 inch metal duct, 35 feet less fittings)
- ICC 2021 International Residential Code, chapter 15, exhaust systems (M1502 clothes dryer exhaust)
Related guides
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