Dryer Vent Cleaning & Repair Guide

Dryer vent maintenance is the single highest-ROI fire-prevention task in your house. Clogged vents cause roughly 15,000 U.S. house fires every year, hundreds of millions in property damage, and dozens of deaths — and almost all of it is preventable with an hour of work once a year. This guide covers how to spot a clogged dryer vent, the real safety risks, and a step-by-step cleaning process you can do yourself.

Why dryer vent maintenance matters

Every load of laundry sheds lint. The lint trap catches most of it, but a meaningful fraction escapes into the vent duct behind the dryer and slowly builds up along the run to the outside wall. Lint is extremely flammable, and a dryer's heating element runs at 550–700°F. Add restricted airflow — which forces the dryer to run hotter and longer — and you have the exact conditions for a duct fire.

The U.S. Fire Administration attributes 34% of dryer fires to failure to clean the appliance. It's the #1 cause. And unlike most home fires, dryer fires almost always start inside a wall cavity where you can't see or reach them.

7 signs of a clogged dryer vent

• Clothes take two cycles to dry. The single most common symptom.
• The dryer or laundry room feels unusually hot during a cycle.
• A burning or musty smell when the dryer runs.
• The exterior vent flap doesn't open or barely flutters during a cycle.
• Excessive lint around the lint trap or on clothing after drying.
• The dryer shuts off mid-cycle — a thermal-limit trip from overheating.
• It's been more than a year since the vent was cleaned. Assume it needs it.

How often to clean a dryer vent

• Lint trap: every single load.
• Full vent duct: at least once a year for a typical household.
• Heavy use (large family, pet bedding, daily laundry): every 6 months.
• Long duct runs (over 25 feet or multiple elbows): every 6 months.

Tools you'll need

• Dryer vent cleaning kit with flexible rods and a rotating brush head (~$25–40)
• Cordless drill (the brush attaches to the drill for rotation)
• Vacuum with a hose attachment — shop vac preferred
• Screwdriver or nut driver for the vent clamp
• Flashlight, dust mask, work gloves

Step-by-step: how to clean a dryer vent

1. Unplug the dryer (and shut off the gas valve if it's a gas dryer). Non-negotiable.
2. Pull the dryer away from the wall just enough to access the vent connection.
3. Disconnect the vent duct from the back of the dryer by loosening the clamp.
4. Vacuum the dryer's exhaust port and the first accessible section of duct.
5. Go outside to the exterior vent. Remove any cover or screen. This is where you'll do the main brush work.
6. Attach the rotating brush to the drill, feed it into the exterior vent, and run the drill on low while slowly pushing the rods deeper. Add rods as you go. Pull back and forth to break up the lint.
7. Vacuum out everything the brush loosened — from both the exterior vent and the dryer end.
8. Clean the exterior vent flap and confirm it opens freely. Replace it if it's cracked or stuck.
9. Reconnect the duct, tighten the clamp, push the dryer back — but leave a few inches of clearance so the duct doesn't kink.
10. Run a 15-minute test cycle on air-only. Go outside and confirm strong airflow at the exterior vent.

When to repair or replace the vent duct

Cleaning solves 90% of dryer vent problems. The other 10% is bad ductwork. Replace any vent duct that shows these issues:

• Foil or vinyl accordion-style ducting. These are code violations in most jurisdictions and trap lint at every ridge. Replace with smooth-wall rigid metal duct.
• Crushed or kinked sections behind the dryer.
• Vent runs longer than 35 feet (subtract 5 feet per 90° elbow). Long runs need a booster fan, not just cleaning.
• Exterior vent that terminates in the attic, crawlspace, or soffit.Dryer vents must exhaust directly outside — always.
• Screened exterior caps. The screen catches lint and clogs instantly. Use a louvered cap with no screen.

When to call a professional

Hire a certified vent cleaner (typically $100–200) if:

• The vent runs through walls, ceilings, or across an attic and you can't reach it.
• You cleaned it and symptoms didn't improve — there may be a bird nest or a collapsed section.
• You live in a condo or apartment where the vent shares a chase.
• It's been more than 3 years and you've never had it professionally inspected.

Turn it into a recurring task

The homeowners who never have a dryer fire aren't lucky — they just have this task on a calendar. Log "clean dryer vent" as a yearly maintenance task in MaintFolio and it schedules itself, reminds you before it's due, and keeps a service history you can hand to a buyer someday. Pair it with the rest of your home maintenance checklist and it becomes automatic.

Bottom line: one hour a year, $30 in tools, and dryer vent maintenance stops being the leading cause of house fires in your home. Clean the trap every load, clean the duct every year, and replace foil ducting with rigid metal. That's the whole playbook.