How Often Should Smoke Detectors Be Replaced?

Time Frame

• Newer smoke detectors have approximately an 8- to 10-year lifespan of reliable service, according to U. S. Fire Administration. Change them when they they reach that age, even if they still seem to be functioning properly. Replace all the detectors when you move into a new home if you are unsure of their age. The City of Dayton, Ohio, warns that older models have a 30 percent failure rate within their first decade, so do not take a chance with units of an unknown age. Use a marker to write the purchase date inside your new detectors so you will remember when to replace them.

Reason

• Ten-year-old smoke detectors should be replaced because they no longer function as efficiently, according to the National Fire Protection Association. Their detection sensitivity can drop, even if they are still functioning, and they are more likely to go off with false alarms from outside factors such as humidity or dust in the unit. Test units regularly, regardless of age, with the test button or canned smoke.

Considerations

• Smoke detector batteries need regular replacement, regardless of the unit's age. Change the batteries annually on an easy-to-remember date, such as the Daylight Savings Time clock change, New Year's Day or your birthday. Install new batteries even if the present ones still seem to be good because they could fail unexpectedly. Put in new batteries immediately if a smoke detector starts to "chirp" with a low power warning. The U. S. Fire Administration recommends vacuuming your detectors occasionally to remove dust, cobwebs and small bugs.

Replacement

• You have two options when replacing old smoke detectors, photoelectric or ionization units, each of which senses the presence of smoke in a different way. Smoke interrupts the electric current in ionization smoke detectors and interrupts a light beam in photoelectric models. The U. S. Fire Protection Association explains that ionization units are best at alerting you to large, fast-moving blazes, while photoelectric detectors work best for slow, smoldering fires. Some manufacturers sell detectors that use both technologies.