Several things may be causing your Kidde carbon monoxide alarm to sound or chirp. Understanding what the beep pattern indicates is essential to keeping your home and family safe, especially if a CO beep is notifying end-of-life mode, since then it can no longer detect carbon monoxide.

Beat the beep and keep your home safe from the harmful and potentially fatal effects of carbon monoxide (CO) poisoning. Here are the different ways and patterns in which a carbon monoxide alarm can beep to signal a message.

Hint: If you installed CO alarms 5-7 years ago, it's time to install new carbon monoxide detectors.

Continuous Four-Beep Alarm Pattern

When the carbon monoxide alarm senses a dangerous level of CO gas, the unit will emit a loud alarm pattern. The alarm pattern is four short beeps – followed by five seconds of silence – followed by four short beeps.* This could mean that:

Consistent Chirping

If your carbon monoxide alarm is chirping or beeping once every 60 seconds, it may signify:

  • Low Battery – The carbon monoxide batteries need to be replaced.
  • End of Life Warning – Seven years after initial power up, a Kidde CO alarm will begin chirping every 30 seconds. The chirp will not stop until the unit is powered off, and it’s vital to replace the carbon monoxide alarm immediately since it can’t detect CO when it enters end-of-life mode.
  • Alarm Malfunction – The alarm chirping every 30 seconds could indicate a unit malfunction. Call our Product Support when this occurs at 1-800-880-6788.
  • Error Code – Check your carbon monoxide alarm for an ERR display and look in your product manual for what the different error codes mean.

Random Intermittent Chirping

If a carbon monoxide alarm is sounding briefly or chirping randomly without a regular pattern, there are a few situations that can cause a CO alarm to intermittently beep and multiple ways to check and address the issue.

One Long, Continuous Squeal

If you hear a long, continuous squeal, this may indicate that your alarm is signaling one of the following:

  • Tamper-resist warning that the unit has been unplugged or has come loose from the outlet.
  • Alarm malfunction which should be resolved by calling 1-800-880-6788.

NOTE: For more information about your specific Kidde carbon monoxide alarm, refer to your product’s user manual.