I did not clean my dryer vent for two years. Not once. I cleaned the lint trap after every load, sure — I thought that was enough. Then a load of towels took three cycles to dry, and the laundry room smelled faintly of something burning.

The vent was packed with a solid wall of lint the thickness of a bath mat. According to the U.S. Fire Administration, dryers cause roughly 2,900 home fires every year, and the leading cause is failure to clean the vent. I was a statistic waiting to happen.

Signs Your Dryer Vent Is Clogged

You do not need to wait two years like I did. Here is what to watch for:

• Clothes take more than one cycle to dry. This is the earliest and most reliable sign.
• The dryer feels hot to the touch on the outside during a cycle.
• There is a burning smell when the dryer is running.
• The laundry room feels humid or smells musty after a cycle.
• The outdoor vent flap does not open when the dryer is running.

How to Clean It Yourself

You need about thirty minutes and a dryer vent cleaning kit — a brush on a long flexible rod that attaches to a drill. They cost about fifteen to twenty dollars at any hardware store.

1. Unplug the dryer. Seriously. Do not skip this.
2. Pull the dryer away from the wall and disconnect the vent duct from the back.
3. Go outside and remove the vent cover from the exterior wall.
4. Run the brush through the duct from inside out, then from outside in. Spin it with the drill to knock lint loose.
5. Vacuum everything — the duct opening, the back of the dryer, the floor around the area.
6. Reconnect and test. Plug it in, run it on air-only for five minutes, and check that air is flowing freely out the exterior vent.

How Often Should You Do This?

At least once a year. If you have a long vent run (more than ten feet), a large household doing lots of laundry, or pets that shed, do it every six months.

And the lint trap? That needs to be emptied every single load. Even a thin layer of lint reduces airflow and makes your dryer work harder. I know it is annoying. Do it anyway.

After I cleaned mine, the same load of towels dried in forty-five minutes instead of two hours. That alone was worth the thirty-minute clean — plus I stopped worrying my house was going to catch fire while I slept.