Dryer fire prevention: the checklist federal safety agencies publish

What the two agencies agree on

The U.S. Consumer Product Safety Commission and the U.S. Fire Administration both publish short consumer sheets on clothes dryer fires. They are not complicated, and they overlap almost completely. Here is the whole list, in plain language.

Clean the lint filter every load. The CPSC says before or after each load. The USFA says before and after each cycle. Never run the dryer without the filter.

Keep the vent and exhaust duct clear. The CPSC says lint can block airflow, cause excessive heat build-up, and result in a fire in some dryers. That is the mechanism. A blocked duct holds heat in, and lint is the fuel.

Check the outdoor vent while the dryer runs. Both agencies mention it. The flap should open and exhaust air should come out. If not, the vent or the exhaust duct may be blocked.

Check the venting behind the dryer. The USFA says to make sure it is not damaged, crushed or restricted. A transition hose folded flat behind a pushed-back dryer is common and costs nothing to fix.

Clean behind the dryer. Lint collects there too. The CPSC also suggests having a qualified person clean the inside of the dryer chassis from time to time.

Use the right duct. The CPSC says to replace plastic or foil accordion-type ducting with rigid or corrugated semi-rigid metal duct. Most manufacturers specify metal, which gives the most airflow. The flexible plastic or foil kind traps lint more easily and is more likely to kink or crush.

The warning sign to act on

The CPSC names one symptom: if clothing is still damp at the end of a typical drying cycle, or drying takes longer than normal, the lint screen or the exhaust duct may be blocked. If you have started running a second cycle, treat that as the sign. Our guide on the signs of a clogged dryer vent covers the others, including the outdoor flap test.

Special care with soiled clothes

The CPSC calls out clothes soiled with volatile chemicals such as gasoline, cooking oils, cleaning agents or finishing oils. Its advice: wash them more than once if possible, preferably hang them to dry, and if you use the dryer, choose the lowest heat and a cycle with a cool-down period. Do not leave the dried clothes in the dryer or piled in a basket.

What you can do, and what needs a pro

You can do the lint filter, the area behind the dryer, the hose behind the machine, and the outdoor flap check. That covers most of the list.

What is hard to do yourself is the run inside the wall, the attic or up to the roof. In many Valley homes the laundry is upstairs and the duct travels through the attic to a roof cap. You can feel reduced airflow at the outside, but you cannot see what is causing it or confirm it is gone. That is the job we do. Dryer vent cleaning is $129 for a standard wall exit and $179 for a roof or second-floor exit, with an airflow reading before and after. See roof and second-floor vents for why the roof job is priced separately.

If you would rather not pay for a cleaning to find out whether you need one, a camera inspection and airflow test gives you the answer first. For how often to repeat the job, see the how-often guide.