Understand Why Your Smoke Alarm Is Chirping

The fire department comes along and installs a new smoke alarm in the hallway—or maybe it's a carbon monoxide alarm. Either way, the thing starts chirping a few months later. What's up?

Woman on ladder testing smoke detector on ceiling
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The Smoke Alarm Is Chirping

Usually, when a smoke alarm or carbon monoxide alarm is chirping (one quick little beep every one to two minutes or so), it means the battery is dying.

Even if your smoke alarm is attached to your electrical system, it should have a battery backup. When that battery is getting low, the alarm chirps to let you know.

Do not call 911 because your battery is low.

It's important not to ignore the chirping; that's why it's so annoying. If you ignore it long enough, it will stop because the battery is dead and you're no longer protected.

So when the chirping starts, pick up a battery at the store and swap it out. If you're not sure how to do it, contact the manufacturer, ask the guy at the hardware store, or call the non-emergency line at the fire department for advice.

When to Call 911

When a smoke alarm starts beeping, you can usually see the smoke that's causing it. If you see smoke, call 911 and get the heck out of there, fast, whether the alarm beeps or not. 

If you know it was just the steam from the shower that caused the alarm to sound, you can usually address it yourself (fanning the steam away from the alarm usually makes it stop).

As long as you know it was just your shower or the fact that you burnt the toast, you're okay. If you don't know why the alarm is beeping continuously, get out and call 911.

Carbon monoxide alarms are a little different than smoke alarms. When a carbon monoxide alarm starts beeping, there's nothing to see. Carbon monoxide is colorless, odorless, and deadly.

It's important to call 911 for a beeping carbon monoxide alarm, just not a chirping one. If either kind of alarm starts beeping continuously, it's time to get out of the house.

What to Do When

  • Get out of the house and call 911 if either the smoke alarm or the carbon monoxide alarm starts beeping loudly.
  • Change the battery if either alarm chirps one quick little beep every few minutes.
  • If you need more advice, call the nonemergency phone number for your fire department.

To avoid this problem entirely, change your alarm batteries once a year. The United States Consumer Product Safety Commission recommends you change batteries when you change your clocks in the fall.

Keeping fresh batteries in your smoke alarms and carbon monoxide alarms promote peace of mind, not to mention avoiding that annoying chirping sound.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. First Alert. 6 things to know about carbon monoxide alarms.

  2. Home Depot. How to change smoke alarm batteries.

  3. ADT. What you need to know about carbon monoxide.

  4. United States Consumer Product Safety Commission. It's time. Check and change your smoke and carbon monoxide alarm batteries.

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.