It is important that you frequently test your smoke detectors. When you are testing your smoke detector, there are a number of reasons why the alarm might not sound.
• You may not be holding the test button down long enough. Try holding it down for up to 10 seconds (20 seconds on photoelectric models).
• Your battery may not be installed properly or snapped all the way in place. Even if the alarm sounded briefly when the battery touched the terminals, you still need to make sure it is snapped securely in place. If the battery is loose, in cannot power the smoke alarm properly. After installing new batteries, be sure to test your smoke detector.
• Your AC power may not be on. AC and AC/DC units will have a power indicator light (red or green) that shines continuously when they are receiving electrical power.
• If you have a 10-Year model, the smoke alarm may not have been properly activated. If the tab broke away before the alarm was activated, you can use a toothpick to move the switch over to test the alarm.