A carbon monoxide alarm can use different patterns for an active CO alarm, low battery, fault, or end of life. If the pattern indicates CO or you are unsure, move outdoors and follow the manufacturer’s and local emergency instructions.
Treat a CO alarm as a potential emergency
Do not first search for which appliance might be responsible. Move people and pets to a safe location and contact the appropriate emergency or utility service for your area.
Do not silence it and go back to sleep
Carbon monoxide cannot be reliably seen or smelled. The absence of symptoms does not prove that the environment is safe.
Once safe, identify the beep pattern
The manual may distinguish active alarm, low battery, fault, and end-of-life patterns. That distinction helps with maintenance, but it should not delay evacuation during a CO alarm.
The source needs investigation, not just the alarm
After a confirmed alarm, fuel-burning equipment, venting, and chimneys may need inspection before reuse as directed by professionals or authorities.
Sources
- U.S. Consumer Product Safety Commission — Carbon Monoxide Information Center — Carbon monoxide risks, alarms, placement, and response to an activation.