Dryer vents don’t get much attention until something goes wrong. But lint is flammable, it builds up out of sight, and blocked vents are a leading cause of home dryer fires according to fire-safety agencies. The good news is that a clogged vent tells you it’s clogged well before it becomes dangerous. Here’s what to look for.
1. Clothes take more than one cycle to dry
This is the earliest and most reliable sign. When the vent is clear, a normal load dries in one cycle. When lint restricts the airflow, moist air can’t leave the drum, and the dryer runs and runs. If you’ve started habitually running loads twice, the vent is the likely cause, not the dryer.
2. The dryer is hot to the touch
The top of the dryer and the clothes coming out of it should be warm, not hot. Excess heat means the air isn’t moving. That heat is also what ignites lint.
3. A burning smell
Any burning smell from the laundry room means stop using the dryer and get the vent checked. Lint that’s smoldering in the duct can flare.
4. The exterior vent flap doesn’t open
Go outside while the dryer is running. The flap on the vent hood should be open and you should feel a strong flow of warm air. If the flap barely moves, or you see lint packed around the opening, the run behind it is blocked.
5. It’s been more than a year
Even with no symptoms, a dryer vent should be cleaned about once a year. Longer vent runs, runs with several bends, and households that do a lot of laundry may need it more often.
What a proper cleaning involves
Cleaning the lint screen is not the same thing. The screen catches only part of the lint; the rest goes into the duct. A proper cleaning clears the full run, from the connection behind the dryer all the way to the exterior hood, using a rotary brush and a vacuum so the lint is removed rather than pushed further along. It should also include a check of the exterior hood, because a broken or missing flap lets cold air, lint and pests back in.
The two-minute check
Next time you run a load, walk outside and look at the vent. If the flap is open and the air is strong, you’re fine for now. If not, it’s time to have it cleaned. It’s a small job, and it’s some of the cheapest fire prevention there is.
