Smoke alarms should be installed on every level of your home, inside each bedroom, and outside sleeping areas. Once installed, it’s important to test alarms monthly by pressing the test button and to replace batteries at least once a year, unless you have a sealed 10-year battery unit. Even hardwired alarms require testing and regular checks. Remember, smoke alarms don’t last forever—replace all units at least every 10 years, or sooner if they fail to respond properly during testing.