Smoke & Carbon Monoxide Alarms

🔥 Smoke & Carbon Monoxide Alarms: What the Beeps Mean 🔥

Provided by the DuPont Fire Department

Working smoke and carbon monoxide (CO) alarms save lives. Understanding what your alarms are trying to tell you is key to keeping your household safe. Here’s what you need to know:

🔊 Alarm Sounds & What They Mean

  • One beep every 30–60 seconds
    ➤ Low battery. Replace the battery as soon as possible.

  • Three loud beeps (pause, repeat)
    ➤ Smoke detected. This is an emergency—get out, stay out, and call 9-1-1.

  • Four loud beeps (pause, repeat)
    ➤ Carbon monoxide detected. Leave your home immediately and call 9-1-1 from a safe location.

  • Chirping even after changing the battery
    ➤ The unit may be expired and needs to be replaced.

⚠️ Note: Each manufacturer may use slightly different sounds or patterns. Always check your alarm’s manual for the most accurate information.

✅ Alarm Maintenance Tips

  • Test alarms monthly by pressing the test button.

  • Replace batteries at least once a year, or sooner if you hear a low battery beep.

  • Replace smoke alarms every 10 years.

  • Replace carbon monoxide alarms every 5–7 years, depending on the manufacturer’s recommendations.

  • Keep alarms free of dust and cobwebs and never paint over them.

📞 When to Call for Help

If your alarm goes off and you smell smoke, see fire, or suspect carbon monoxide exposure:
Don’t wait—call 9-1-1 immediately.

❓ Have Questions?

If you’re unsure about a sound your alarm is making, need help checking your devices, or want more information on home fire safety, please contact the DuPont Fire Department.
We're here to help keep you safe.