Do Smoke Detectors Need to Be Replaced?

Failure

• Smoke alarm failure is most frequently linked to either missing, disconnected or dead batteries. Many times people remove the batteries or disconnect the detector from a built-in system by cutting the wires if the alarm gets set off when they are cooking.

Batteries

• Batteries should be replaced in your smoke alarms frequently. Experts from the NFPA recommend that you replace batteries at a minimum of once a year, but adhere to the manufacturers' instructions if they require that you do it more often. Many people recommend that you do it every time you change your clocks for daylight savings time, so you don't forget. Your smoke alarm should also "chirp" when the battery is low.

Alarm Placement

• Avoid placing smoke detectors against outside walls if possible, since the colder air in winter has the potential to cause them to fail in the event of a fire. The NFPA also recommends that you create a smoke detector system that will sound all alarms when one goes off. To prevent false alarms, keep the detectors at least 20 feet from furnaces and ovens, 10 feet from areas of high humidity, such as showers, and 3 feet from heating and air conditioning vents.

Alarm Replacement

• All smoke alarms will need to be replaced at some time or another. Test your alarm once a month using the test button, and replace it if the test fails. Replace all detectors anyway every 10 years, as recommended by the NFPA and leading manufacturer of smoke detectors in the United States, Some manufacturers may call for replacing them more often. If you're moving into a new home, ask the previous owner or tenant about the last time the alarms were replaced.

Reasons for Failure

• The sensing chamber inside the smoke alarm detects smoke particles, not heat or flames, and its sensitivity may decrease over time. Richard Bukowski, a manager at the Center for Fire Research, led a study which discovered that fire detectors fail at a rate of 3 percent each year. Painting on a smoke detector can also render it dysfunctional, since the paint may clog the smoke entry holes and possibly damage the inner circuitry.