The U.S. Fire Administration logs nearly 3,000 dryer fires every year. About a third of those start the same way: lint buildup in the exhaust vent ignites from the dryer's heat.
The fire risk is real but the fix is unglamorous. The vent that runs from the back of your dryer to the exterior wall slowly fills with lint over months and years. Even with a clean lint trap, fine fibers escape and accumulate in the corrugations and elbows of the vent run. Once enough lint is in there, two things happen:
1. The dryer has to work much harder to push air out, which makes it run hotter and longer. 2. The accumulated lint sits in close proximity to hot exhaust gases.
Eventually that combination is enough to start a fire.
Signs your vent is clogged:
- Clothes take longer than one cycle to dry (or two cycles for heavy items) - The dryer top is very hot to the touch after a cycle - The laundry room gets warm and humid during a cycle - You can see lint piled up at the exterior vent flap - The exterior vent flap doesn't open when the dryer is running - A burning smell
If you see any two of those, schedule a cleaning before the next load.
How often to clean it:
- Annually for typical use (a few loads a week, no pets) - Every 6 months if you have a long vent run, multiple bends, heavy pet shedding, or you do laundry daily
What you can do yourself vs. what needs a pro:
You can clean the lint trap every load (you should, anyway) and brush out the area behind the trap with a vacuum. The vent run itself, especially the section that goes through walls or up to the roof, needs a specialized brush and a vacuum — that's the part professionals handle.
The whole job takes 30 to 60 minutes. Cheaper than a fire, much cheaper than replacing a dryer that's been running too hot for too long.