Clean a dryer vent at least once a year, and every six months if your dryer runs most days. Unplug the dryer, pull off the hose, spin a brush on a drill through the duct, then blow out the rest with a leaf blower. Then fix what clogs it in the first place: sharp 90-degree bends and a crushed hose.
The National Fire Protection Association says the leading cause of home dryer fires is failure to clean them. The lint screen catches most of the lint. What slips past it settles in the duct, a little every load, until the air can't get out.
A dryer vent is easy to forget because you never see it. Keeping track of when it's due, and lining up the right person when it's more than a weekend job, is part of what our home maintenance plans take off your list.
The water heater is another one that's easy to forget. Here's how often a water heater should be flushed.
How often should you clean a dryer vent?
A dryer vent should be cleaned at least once a year. The NFPA's advice is once a year, or sooner if your clothes start taking longer to dry.
Our own rule is every six months for a household that runs the dryer most days: towels, bedding, sports kit, the lot. A couple doing two loads a week can stay with once a year.
Fall is a good time. The dryer works harder in the colder months, and you want the vent clear before snow can pile up against the hood outside.
It fits in with the rest of the fall jobs in our guide to winterizing your house.
How can you tell a dryer vent is clogged?
A clogged dryer vent usually shows itself in the laundry room first. Watch for these signs:
- A normal load needs a second cycle to dry.
- The top of the dryer, or the clothes, feel hotter than usual.
- The laundry room gets warm and humid while the dryer runs.
- A scorched or burning smell. Stop using the dryer if you notice this.
- Outside, the flap on the vent hood barely moves, or lint is stuck around it.
- Some newer dryers show a vent warning on the display.
The quickest check is the hand test. Run the dryer on heat, go outside, and hold your hand near the vent hood. You should feel strong, warm air and see the flap pushed wide open. Weak, damp air means something is in the way.
What do you need to clean a dryer vent?
Dryer vent cleaning takes a few tools you can buy at any hardware store:
- A dryer vent brush kit: a round 4-inch brush and flexible rods that screw together.
- A cordless drill with an adjustable clutch.
- A leaf blower. A battery one is easier, since there's no cord to drag through the house.
- A shop vacuum with a narrow nozzle.
- Aluminum foil tape (the silver HVAC tape, not cloth duct tape).
- A screwdriver or nut driver for the hose clamps.
- Painter's tape, safety glasses and a dust mask.
How do you clean a dryer vent, step by step?
Cleaning an electric dryer vent takes these steps. If your dryer runs on gas, read the next section before you move anything.
- Turn off the power. Unplug the dryer. If you can't reach the plug, switch off the dryer's breaker at the panel.
- Slide the dryer out slowly, just far enough to work behind it. Watch the hose as it moves so it doesn't tear.
- Disconnect the hose at the dryer and at the wall. Inspect it in good light: tears, pinholes, crushed sections, lint packed at the ends.
- Vacuum the outlet on the back of the dryer, the floor underneath, and the slot the lint screen sits in.
- Open the outside flap. Tape it open with painter's tape, if you can reach it from the ground or a six-foot ladder.
- Brush the duct from the wall opening. Screw the brush onto two rods, put the end in the drill, set the clutch low, and feed it in spinning clockwise only, including on the way out. The instructions that come with these kits explain why: spin it the other way and the rods unscrew inside the duct. Add rods as you go until the brush reaches the hood.
- Blow it out. Hold the leaf blower nozzle to the wall opening, stuff a rag around the gap, and give it a few short bursts. Lint shoots out of the hood outside, so make sure nobody is standing there and nothing is parked in front of it. This step clears what the brush loosened.
- Clean the hood outside. Pull lint off the flap, check it swings freely, and take the tape off.
- Reconnect and test. Reattach the hose, push the dryer back, plug it in and run it on heat. Go outside and do the hand test again.
What if the dryer runs on gas?
A gas dryer is connected to the house gas line by a flexible connector, and sliding the dryer out puts strain on that connection. We don't disconnect or reconnect gas appliances, and we'd suggest you don't either.
Have a licensed plumber or appliance technician pull a gas dryer out and put it back. They'll close the gas valve on the pipe behind the dryer first and check the connection afterward. It's still worth knowing where that valve is. You can clean the lint screen and the outside hood yourself without moving the dryer.
If you ever smell gas, leave the house and call your gas utility or 911 from outside.
Why does a magnetic dryer vent connector help?
A magnetic dryer vent connector replaces the hose clamp at the wall with a ring magnet, so the hose snaps on and pulls off in a second. It sounds like a gadget. It solves the hardest part of the job.
Reconnecting a dryer hose usually means reaching blind behind the dryer, in a few inches of space, and tightening a clamp you can't see. That's when hoses get crushed, kinked, or left half on, blowing lint into the wall instead of outside. With a magnetic connector you push the dryer back and the magnet finds the fitting on its own. Taking it apart is so easy that the cleaning actually gets done. In our opinion it's the best small upgrade you can make in a laundry room.
Check two things before you buy one. The hose that comes with it should be metal, not thin foil or plastic; Whirlpool's installation guide says not to use plastic or metal foil vent. And the wall fitting should match a standard 4-inch duct.
Why should a dryer vent have as few 90-degree bends as possible?
Every 90-degree bend in a dryer vent slows the air and gives lint a corner to settle in. Fast air carries lint outside. Slow air drops it in the duct.
Dryer makers build this into their limits. In one Whirlpool installation guide, the longest allowed vent run drops from 64 feet with no elbows to 27 feet with four, roughly 10 feet lost for each 90-degree turn.
What that means in your laundry room:
- Run the duct as short and straight as the room allows.
- Where a turn can't be avoided, a gentle sweep moves air better than a tight elbow.
- Don't let the hose behind the dryer make its own bends. Extra hose sags and loops, so cut it to length.
- If the laundry was moved upstairs in a renovation, the duct is probably long with several turns. That vent needs cleaning more often.
What should you do about holes in a dryer vent hose?
A hole in a dryer vent hose leaks warm, damp, linty air into the room or into the wall behind the dryer. For a small hole, aluminum foil tape will seal it for now. Press it flat all the way around so there's no loose edge for lint to catch on. Tape buys you time. Plan to replace the hose.
Seal the joints with foil tape too, and hold them with clamps. Never put screws through a dryer duct. The tips poke inside and snag lint. Cloth duct tape dries out in the heat and lets go.
If the hose is white plastic, or thin foil that crushes in your hand, replace it with semi-rigid metal duct.
What else keeps a dryer vent clean?
A few habits keep a dryer vent clean between cleanings:
- Empty the lint screen every load. Every load, not every other one.
- Wash the lint screen every few months. Dryer sheets leave a waxy film you can't see. Hold the empty screen under the tap. If the water pools instead of running through, scrub both sides with dish soap and a soft brush, and let it dry fully before it goes back in.
- Check the outside hood after storms and snow. A hood buried in snow can't open.
- Look for nests in spring. Birds like a warm vent hood. Don't cover the hood with a fine screen to keep them out, because it clogs with lint. A hood with a flap or louvers that close on their own is the better fix.
- Don't run the dryer when you're out or asleep. The NFPA recommends against it, and it's worth remembering on the morning you leave for a trip.
When to call a professional
Call a dryer vent cleaning company, a plumber or an appliance technician when:
- The dryer runs on gas and needs to be moved.
- The vent comes out on the roof, or higher than you can reach from a six-foot ladder. Check the hood from the ground and leave the climbing to someone with the right equipment.
- The duct runs inside walls or ceilings, or is longer than your brush kit reaches.
- The brush gets stuck, or a rod comes loose inside the duct.
- You smell burning, or the dryer shuts itself off mid-cycle or stops heating even after the vent is clean.
- You find crushed or disconnected duct inside a wall or ceiling.
If you'd like someone else to remember when the vent is due and book the right person, that's part of our home maintenance service.
Frequently asked questions
Can you clean a dryer vent from the outside?
Yes, you can brush a dryer vent from the outside hood toward the dryer, as long as you can reach the hood safely from the ground or a six-foot ladder. Disconnect the hose inside first so the lint has somewhere to go. Many people brush from both ends to meet in the middle on a long run.
Is foil dryer vent hose safe?
Thin foil and white plastic dryer hoses crush and tear easily, and dryer makers such as Whirlpool tell you not to use them. Semi-rigid or rigid metal holds its shape and is easier to clean. If you have foil or plastic now, replacing it is a small, cheap job.
Does a clean dryer vent lower energy bills?
A clear dryer vent dries clothes faster, so the dryer runs for less time. Whirlpool's guide notes that an overly long vent means longer drying times and more energy use, and a clogged vent works against the dryer in the same way.
Do ventless dryers need vent cleaning?
Ventless dryers (condensing and heat pump models) have no outside duct, so there's nothing to brush. Their lint filters still need regular cleaning, and some models have more than one. The owner's manual says where they are and how often.
If you'd rather someone else kept track of the dryer vent, along with everything else in the house, that's what we do.
The Home Steward is a home management service based in Summit, New Jersey, run by Sebastian and Kory, caring for homes in Summit, Chatham, Short Hills and Millburn.
