Smoke detectors should be checked once a month for proper working conditions. Follow the alarm manufacturer's instructions for testing the detectors. Smoke alarms all have a button to push to check the alarm. This test button can also be pushed to check how sensitive to smoke your alarm is to set it off. The alarm should be replaced immediately if the test button does not work. Do not use an open flame to test the alarm in any circumstance.
Smoke alarms are usually very reliable but can malfunction. If a battery-powered smoke alarm begins to chirp or emit a low-power sound, the battery should be replaced immediately with a new one. If an alarm begins to sound while cooking, the alarm may need to be moved farther away from its current position near a kitchen or bath.
Smoke alarms do not require a lot of maintenance. The batteries should be changed twice a year. One good way to remember to do this is to change the batteries when you change the time in the spring and fall. Occasional vacuuming and dusting will keep the alarm clear of dirt and insects.
Smoke alarms last about 10 years. After that they should be replaced even if the alarm is working correctly. Newer model smoke alarms are more reliable than older models. Therefore it makes sense to replace an alarm that has reached its age limit with a newer model.