Why is my smoke or carbon monoxide alarm chirping?

Question

My smoke or carbon monoxide alarm is chirping intermittently. Why is that?

Answer

The same factors that cause unwanted alarms in smoke alarms (smoke detectors) and carbon monoxide alarms can cause intermittent alarms: dust, insects, and power interruptions. The ‘chirp’ may also be caused by:

  • Low battery.
    This is the most probable cause. Many smoke alarms have a low battery chirp to alert you to change the battery when its power is running low. Make sure you regularly change their batteries.

  • A different device or appliance.
    Security systems, monitors, carbon monoxide alarms, and other devices have similar low battery or alert signals.

  • Improper wiring on 240v smoke alarms.
    240v smoke alarms will chirp every five seconds if the interconnect wire is grounded. The orange interconnect wire should NEVER be grounded; it should only be used to interconnect other smoke alarms or compatible devices.

Regardless of the manufacturer’s suggested battery life, you must replace the battery immediately once the unit starts ‘chirping’ to let you know that its battery is getting low. A battery with power is vital for a reliable, functioning smoke or carbon monoxide alarm!