Kidde KN-COSM-B-RF User Manual page 15

If your CO alarm fails to test properly, or if its self-diagnostic test
reveals a malfunction, immediately have the unit replaced. This
alarm will not monitor CO levels while in an error condition.
CO alarms can only sense CO that reaches the unit's
sensor. It's possible that CO may be present in other
areas without reaching the alarm.
The rate at which CO reaches the alarm may be affected by:
• Doors or other obstructions.
• Fresh air from a vent, an open window or other source.
• The presence of CO on one level of the home and a CO
alarm installed on a different level. (For example, CO in the
basement may not reach an alarm on the second level.)
For these reasons, we recommend you provide complete
coverage by placing a smoke/CO alarm on every level of the
home. Please carefully read all information in the Installation
Guide section on properly installing this smoke/CO alarm.
CO alarms should not be used to detect the presence
of natural gas (methane), propane, butane or other combustible
fuels.
Instruct children never to touch, unplug or otherwise interfere
with the alarm. Warn children of the dangers of CO poisoning.
Carbon Monoxide Information 15