Clean the dryer vent duct at least once a year, and clean the lint screen after every single load. Make it every six months if you dry several loads a day, have a shedding dog or cat, or your duct runs a long way to the outside wall. Clothes that suddenly take longer to dry mean the vent is due now, whatever the calendar says.
That annual figure comes from the NFPA's clothes dryer safety tips, which say to clean lint out of the vent pipe once a year, or more often if drying takes longer than normal. Whirlpool's venting guidance gives every one to two years, adjusted for how much you use the dryer and what you dry in it. Once a year is the safer of the two.
Why the vent matters more than it looks#
The NFPA puts it bluntly: the leading cause of home dryer fires is failure to clean them. When it packs into the duct, hot air can't get out, the dryer runs hotter and longer, and the CPSC warns that this heat build-up can start a fire.
The lint screen catches most of it but not all. Some slips past and settles in the duct, especially at bends and low spots, so a clean screen tells you nothing about the duct behind the machine.
How often to clean each part#
| Part |
How often |
Notes |
| Lint screen |
Every load |
Before or after each load, never run without it |
| Lint screen wash |
When lint sticks to the mesh |
Rinse with warm water and a soft brush, dry fully |
| Lint screen housing and drum |
Monthly |
Vacuum lint from the slot the screen sits in |
| Moisture sensor bars |
Every few months |
Damp cloth with mild soap |
| Vent duct |
Once a year, every 6 months with heavy use |
Sooner if drying slows |
| Outside vent hood |
A few times a year |
Also after snow, storms, and nesting season |
| Behind and under the dryer |
When you clean the duct |
Lint collects on the floor and back panel |
The screen washing, housing, and sensor bar intervals are from Samsung's dryer care checklist, which also says to inspect the exhaust vent at least once a year.
Signs your dryer vent is clogged#
- A normal load now needs a second cycle, or clothes come out damp at the end of a cycle that used to finish them.
- The outside flap doesn't open, or you can't feel warm air coming out while the dryer runs.
- The top of the dryer or the clothes feel unusually hot.
- Lint is building up around the outside hood or on the wall below it.
- The laundry room gets humid or warm when the dryer is on.
The CPSC lists the first two as signs that the lint screen or the duct is blocked. If you smell burning or see smoke, stop the dryer and switch it off. If there's any sign of fire, get everyone out and call the fire department from outside.
How to clean a dryer vent yourself#
This works for a typical setup: dryer against an outside wall, a short duct, and a hood you can reach from the ground. You'll need a dryer vent brush kit (flexible rods that screw together with a brush head), a vacuum with a hose attachment, and a screwdriver or nut driver for the clamps.
- Unplug the dryer. With a gas dryer, leave the gas line connected and move the machine slowly so the flexible connector doesn't get strained or kinked. If it looks old, stiff, or damaged, stop and call a pro.
- Pull the dryer out far enough to reach the back. Loosen the clamp and slide the duct off the dryer's exhaust outlet.
- Vacuum the dryer's outlet and as far into it as the hose will go. Lint tends to pile up right at this joint.
- Feed the brush into the duct from the inside end and rotate it as you push, working toward the outside. Pull it back out and empty the lint every few feet.
- Go outside, open or remove the hood cover, and clear lint from the hood and the last section of duct. Check the flap swings freely.
- Vacuum behind and under the dryer, then refit the duct and tighten the clamp.
- Push the dryer back without crushing the duct, plug it in, and run it on a no-heat or air setting for a few minutes. Go outside and check that air is coming out strongly.
The CPSC's reminder at step 6 is worth repeating: reconnect the ducting to both the dryer and the outside vent before using the dryer again. A duct left loose behind the machine blows hot, lint-laden air into the room.
What kind of dryer duct should you have?#
If the duct behind your dryer is white plastic or thin silver foil that crumples like a slinky, replace it. The CPSC recommends rigid or corrugated semi-rigid metal, because plastic and foil ducts trap lint more easily and kink or crush, which cuts airflow. Whirlpool specifies a 4-inch metal duct, as short and straight as possible, with the outside hood at least 12 inches off the ground.
When to call a professional#
Hire a dryer vent cleaning service if the vent exits through the roof, the duct runs more than a few feet through walls or ceilings, you can't move the dryer safely, or you find a bird's nest you can't reach. Gas dryers deserve extra caution: the NFPA recommends having a professional check that the gas line and connection are intact and not leaking. The CPSC also suggests having a qualified technician clean lint out of the inside of the dryer cabinet periodically.
Do condenser and heat pump dryers need vent cleaning?#
No, because they don't vent outside. They have a lint filter that needs cleaning after every load, plus a second filter or a condenser that needs cleaning on the schedule in the manual or when the display shows a filter alert. Skip the duct-cleaning reminder for these and set one for the condenser instead.
Can you leave the dryer running when you go out?#
The NFPA says not to run the dryer when you leave home or go to bed. A clean vent lowers the risk, but you still want to be around to notice a burning smell. Make sure there's a working smoke alarm near the laundry area too.
Put the duct cleaning on the calendar the same month every year, alongside the other jobs on your home maintenance checklist. A yearly reminder in ChoreLists.com for the duct, plus a monthly one for the screen housing, covers it. The washer next to it has its own monthly routine, covered in how often to clean your washing machine.