Dryer vent cleaning: a step-by-step guide

The short answer: dryer vent cleaning means clearing lint out of the duct that carries hot air from your dryer to the outside, not just emptying the lint screen. Lint is flammable.

• Signs of a clog: clothes need two cycles or the laundry room feels very hot
• 8 steps: unplug, pull the dryer out, disconnect the duct and brush it from the inside
• How often to clean, by part
• DIY or hire a pro, and how to tell the cleaning worked
• Next step: Plan it with the Home Maintenance Log ($5.99).

Dryer vent cleaning means clearing lint out of the duct that carries hot air from your dryer to the outside, not just emptying the lint screen. It matters because lint is flammable: the U.S. Fire Administration reports that failure to clean was the leading factor in home clothes dryer fires from 2018 to 2020, at 31 percent. Here is how to tell your vent is clogged, how to clean it yourself step by step, how often to do it and when to call a professional.

Our Home Maintenance Log printable has monthly, seasonal and annual checklists plus service and repair records, so the date of the last vent cleaning is written down.

Why dryer vent cleaning matters

The National Fire Protection Association's report on home fires involving clothes dryers estimated about 13,820 home dryer fires a year from 2014 to 2018, causing 7 deaths, 344 injuries and $233 million in property damage each year. Failure to clean was the leading factor, in 32 percent of them, and dust, fiber or lint was the item that first caught fire in 27 percent.

A clogged vent also costs money. When hot, damp air cannot escape, clothes take longer to dry, the dryer runs longer and parts like the heating element and thermal fuse wear out sooner.

Signs your dryer vent is clogged

If you smell burning, stop the dryer, unplug it and do not use it until the vent is cleared.

How to clean a dryer vent in 8 steps

1. Unplug the dryer. For a gas dryer, also turn off the gas valve.
2. Pull the dryer away from the wall carefully, without kinking the duct or gas line.
3. Disconnect the duct from the back of the dryer by loosening the clamp.
4. Vacuum the dryer outlet and the floor, wall and back panel. The USFA dryer safety flyer reminds you not to forget the back of the dryer, where lint builds up.
5. Brush the duct from the inside. Feed a vent brush on flexible rods into the wall duct, twisting as you go, and pull out lint. Vacuum as you work.
6. Clean from the outside. Remove the outdoor vent cover, clear lint and debris, and brush inward.
7. Check the duct. The flyer says to make sure the venting system is not damaged, crushed or restricted. Replace plastic or foil duct with metal.
8. Reconnect and test. Reattach with a clamp or foil tape (not screws, which catch lint), push the dryer back without crushing the duct, run it on air-only and check that the outside flap opens.

How often to clean, by part

The USFA says to clean the lint filter before and after each cycle and never to use the dryer without it. The yearly duct schedule is a common rule of thumb rather than a legal requirement, so check your dryer manual.

DIY or hire a professional?

You can usually do it yourself if the vent is short (a few feet straight to an outside wall), you can reach both ends and the duct is in good shape. Consider a professional if:

• the vent runs through an attic, crawlspace or to the roof;
• the run is long or has several bends;
• you find a crushed or disconnected duct inside a wall;
• a bird or rodent nest is in the vent;
• clothes still dry slowly after you have cleaned it.

The flyer also recommends having your dryer installed and serviced by a professional.

Other dryer safety habits

While you are in the laundry room, our guide on how to clean a washing machine shows how to stop mold and odors in the washer.

• Do not run the dryer when you are asleep or away from home.
• Keep the area around the dryer clear of boxes, clothes and cleaning products.
• Do not dry items stained with gasoline, cooking oil or other flammable liquids without washing them well first, and follow the label. Here's how to get oil out of clothes before they go in the dryer.
• Make sure the outdoor vent cover opens when the dryer is running.
• Keep a working smoke alarm nearby and a carbon monoxide alarm if you have a gas dryer.

How to clean dryer vent from the outside

The outside end of the duct clogs too, and it is the part most people skip. With the dryer unplugged:

1. Find the exterior hood. It is usually on a wall near the laundry room, but it can also be on the roof, under a deck or in a soffit.
2. Take off the cover if it unscrews or unclips. Many building codes do not allow a screen on a dryer exhaust hood because screens catch lint. If yours has one, ask a contractor about a hood with a simple flap instead.
3. Pull out the lint you can reach with a gloved hand, then vacuum the opening.
4. Brush inward toward the dryer with your rods, then go back inside and vacuum what came loose.
5. Check the flap. It should swing freely and close when the dryer is off, so birds and rodents cannot move in.

If the vent comes out on the roof, do not climb a steep, wet or high roof to reach it. A roof vent is the most common reason to hire a professional.

Choosing a dryer vent cleaning kit

A dryer vent cleaning kit is a set of flexible rods that screw together, a brush head and sometimes a drill adapter and a lint trap brush. Here is what each part is for:

Measure your vent run before you buy. A kit that is too short only cleans the first few feet, which is where you can already see.

Dryer vent cleaning cost: what changes the price

Prices for a professional visit vary by region, so the most useful thing to know is what pushes a quote up or down:

Ask two or three companies for written quotes that say what is included, such as both ends of the duct, the space behind the dryer, reconnecting the duct and an airflow check. Ask whether the price is for the dryer vent alone or bundled with other services. For a short, straight wall vent, a brush kit usually costs less than a single service visit and can be used for years.

How often to clean dryer vent for your household

The once-a-year rule is a starting point. Adjust it to how hard your dryer works:

How to tell the cleaning worked

Time a normal load before you clean, then time it again afterwards. After a good cleaning, a regular load should dry in one cycle, the outside flap should open fully with a strong, warm airflow and the top of the dryer should feel warm rather than hot. If none of that changes, there may be a crushed section or a blockage you could not reach, and it is worth having a professional look.

Keep a record so it actually gets done

A yearly job is easy to forget. Writing it down turns it into a routine. The Home Maintenance Log ($5.99, printable PDF) has monthly, seasonal and annual checklists, an Appliance Log for your dryer's model, purchase date and warranty, Service & Repair Records for each cleaning, Contractor Contacts for the vent service you used and pages for home details. Add "dryer vent" to the fall list so it is done before winter. A bound Home Maintenance Log paperback version is planned; it isn't on Amazon yet, and its page has a Notify me button for one email when it can be ordered.

For the rest of the year's jobs, see our home maintenance checklist, the deep cleaning checklist and the property maintenance log template.