When your carbon monoxide detector chirps 4 times in a row and pauses, this means it has detected unsafe levels of carbon monoxide. This means your entire household should evacuate immediately and seek fresh air.

On First Alert carbon monoxide detectors, check to see if the battery light is yellow or green. If the alarm is chirping and the light is yellow, it means the battery is low. The way to get a carbon monoxide alarm to stop chirping is to replace the battery.

You should… The horn chirps 1x per minute. Low battery warning. Install a new Duracell, Energizer, or Everready battery. The horn sounds 3 chirps every minute. Malfunction warning. CO alarm needs to be replaced. Alarms under warranty should be returned to manufacturer for replacement.