FixPlainly

Smoke alarm chirping: what it means and how to stop it

A short chirp every so often is the alarm asking for attention, often a new battery or, on older alarms, a whole new alarm. A loud, repeating pattern of beeps is different: that’s an emergency.

Last checked against its sources on

Repeating sets of 3 loud beeps means smoke. Get everyone out and call 911 from outside. First Alert and Kidde both use this pattern for smoke.

Which sound is it?

Patterns vary by brand, so check the label on the back of your alarm or its manual. These are the patterns Kidde publishes, with the smoke pattern also used by First Alert:

3 beeps, repeating: smoke detectedLeave now and call 911 from outside.
4 beeps, repeating: carbon monoxide (combination and CO alarms)Get to fresh air and call 911. What to do
1 chirp, then a pause: needs attentionKidde calls this a trouble signal. It often means the battery needs replacing.
2 chirps, then a pause: end of life (Kidde)The whole alarm needs replacing, not just the battery.

How to stop the chirp

  1. Find which alarm is chirping. Wait under each one until you hear it.
  2. Check the label: does it take a replaceable battery, or is it a sealed 10-year alarm?
  3. Replaceable battery: fit a new battery right away. A hardwired alarm with a backup battery needs that battery replaced too.
  4. Sealed 10-year alarm: the battery can’t be changed. The West Virginia State Fire Marshal says to replace the whole alarm right away.
  5. Press the test button to check it sounds.
  6. Still chirping with a fresh battery? Check the date on the back. If it’s near or past 10 years old, replace the alarm.

Don’t take a battery out to stop the noise without replacing it. An alarm with no power can’t warn you.

Replace every 10 years

First Alert, Kidde and the West Virginia State Fire Marshal all say to replace smoke alarms at least every 10 years from the manufacture date on the back. For battery changes, First Alert recommends at least every 6 months for battery-powered and battery-backup alarms; the fire marshal’s fact sheet says at least once a year.

Testing and placement

Test alarms with the test button at least monthly, as the fire marshal’s fact sheet advises; Kidde suggests weekly. Alarms belong inside every bedroom, outside each sleeping area and on every level, including the basement. Keep them at least 10 feet from cooking appliances, mount them high on the wall or ceiling, and never paint over them.

Sources

  1. Why is my smoke detector beeping? The battery in your smoke alarm matters, First Alert
  2. Kidde celebrates NFPA Fire Prevention Week: learn the sounds of fire safety, Kidde
  3. Smoke Alarm Fact Sheet, West Virginia State Fire Marshal
Last checked against its sources on