How to Clean Your Dryer Vent

To clean a dryer vent, unplug the dryer, pull it away from the wall, disconnect the vent duct from the back of the dryer, vacuum the lint from both ends of the duct, push a dryer vent brush through the duct to dislodge packed lint, vacuum again, and reconnect. Do this once a year to prevent fires and maintain efficiency.

The steps

Unplug the dryer and shut off the gas if applicable

Safety first. Unplug the dryer from the wall outlet. If you have a gas dryer, close the gas shutoff valve behind the unit. Never clean a vent with the dryer connected to power.

Pull the dryer away from the wall

Slide the dryer out about 2 feet to give yourself room to work. Gas dryers have a flexible gas line; move slowly and do not kink or stretch it.

Disconnect the vent duct from the dryer

Loosen the clamp or peel off the foil tape securing the vent duct to the back of the dryer. The duct will come off with a gentle twist. Wear gloves because packed lint is dusty and can irritate skin.

Vacuum both ends of the duct

Use a vacuum with a hose attachment to pull loose lint from the back of the dryer, the connector port, and the inside end of the vent duct. Also vacuum the exterior vent hood on the outside of your house. Most of the visible lint comes out in this step.

Run the brush through the full length of the duct

Dryer vent brush kits come with flexible rods that screw together to reach 10 to 20 feet. Attach the brush head and feed it through the duct from whichever end is easier to access. Push and twist as you go to dislodge packed lint from the duct walls. A drill chucked onto the end of the rod speeds this up significantly.

Vacuum again and reconnect

Vacuum any lint that the brush pushed out of the duct. Reconnect the duct to the back of the dryer with a clamp or fresh foil tape. Do not use standard duct tape, which degrades from heat. Push the dryer back into place, plug it in, and run an empty cycle on heat for 10 minutes to confirm everything is connected properly.

Why the vent is the biggest dryer fire risk

The lint screen catches about 75 percent of the lint your clothes shed during a cycle. The rest passes through the screen and travels through the vent duct to the outside of your house. Over a year, that residual lint builds up on the inside walls of the duct, especially around bends and at the exterior vent hood.

Unlike the lint trap, you cannot see the vent duct clog forming. It happens slowly over months. Once the duct is significantly clogged, three things go wrong:

Airflow drops, so clothes take longer to dry and the dryer runs hotter to compensate.
The heating element cycles more frequently, wearing it out faster.
Trapped lint is extremely flammable, and a spark from the heating element can ignite it. This is how dryer fires start.

The U.S. Fire Administration reports about 2,900 dryer fires per year in U.S. homes. Failure to clean is the leading cause. A yearly vent cleaning, paired with cleaning the lint screen before every load, nearly eliminates the risk.

How to inspect before you clean

Before you buy a brush kit, check whether your vent run is one you can handle yourself. Follow the duct from the back of the dryer to where it exits the exterior wall. Count the bends and estimate the length.

Straight run under 15 feet, one or zero bends: Easy DIY with a basic brush kit.
15 to 25 feet, two to three bends: DIY is possible but slower. Consider a drill-powered brush kit.
More than 25 feet, runs through walls or ceilings, or vents to the roof: Hire a professional. Standard brush kits will not reach and you risk breaking a brush rod inside the duct.

What a dryer vent brush kit looks like

A basic kit includes:

A circular brush head that fits a 4-inch duct
Six to twelve flexible fiberglass rods that screw end-to-end
An adapter to connect the rods to a power drill (speeds up the work significantly)

These kits run $20 to $30 at any hardware store or online. One kit lasts many years if you take care not to lose the rod couplers.

Tips for cleaning the exterior vent

The exterior vent hood is as important as the duct itself. Lint piles up at the flap, sometimes propping it partially open. Lint also gets compressed behind the flap by the airflow from inside.

Go outside with a vacuum and clear the hood first, before you start on the duct. Lift the flap and reach behind it with a gloved hand. Bird nests and insect nests are common in unused summer months. Any of those blockages defeats your interior cleaning immediately.

When to just run an empty load after cleaning

After you reconnect the duct and push the dryer back into place, run an empty cycle on the normal heat setting for 10 minutes. This does three things:

Flushes any lint the brush missed through the duct
Confirms the duct is connected properly (no air escaping at the connection)
Lets you feel airflow at the exterior vent hood, which should be strong and steady

If you do not feel good airflow outside, the duct is either still clogged, kinked, or disconnected somewhere. Pull the dryer out again and check before the next load.

How this fits into a maintenance routine

Pair dryer vent cleaning with another annual task so you remember it. Many homeowners do it in fall with gutter cleaning and furnace prep. The job is not hard but it is dusty, so pick a day you are already dressed for rough work. Skip a year and the lint compounds fast. Clean it every year and you are protected from the leading cause of residential dryer fires.

Frequently asked questions

How often should I clean my dryer vent?

Once a year for most households. Clean more often (every 6 months) if the vent run is longer than 15 feet, has multiple bends, or if you dry a lot of heavy items like towels and blankets that shed more lint.

How do I know if my dryer vent is clogged?

The biggest clue is clothes taking longer than one cycle to dry. Other signs: the top of the dryer or laundry room feels unusually hot during a cycle, you notice a burning smell, or you see little or no airflow coming from the exterior vent hood while the dryer runs. Any of these means the vent needs attention now.

Should I hire a pro for dryer vent cleaning?

If the vent run is longer than 15 feet, goes through multiple floors, or has many bends, professional cleaning is worth the $100 to $200. Pros have longer brushes and stronger vacuums. For a simple straight-run vent less than 15 feet, DIY with a $25 brush kit works fine.

What kind of duct should I use?

Rigid metal or semi-rigid aluminum. The foil-faced flexible plastic hoses (the ones that look like slinky tubing) are discouraged because lint catches on the ridges inside. If you find a plastic flex-duct behind your dryer, replace it with rigid metal as soon as you can.