Working Smoke Alarms Save Lives!
Roughly 3 out of every 5 fire deaths happen when there are no working smoke alarms. Make sure you have working smoke alarms on every level of your home, in each bedroom and outside each sleeping area. Test your smoke alarms once every month to make sure they are working by hitting the "test" button.
Smoke alarm batteries should be changed every six months, and smoke alarms should be completely replaced every ten years. Make sure your smoke alarms are placed on the ceiling or high on the wall. Keep smoke alarms away from the kitchen and at least ten feet from the stove to prevent false alarms.
Here's more on smoke alarm maintenance and installation.