Smoke detectors can seem like time detectors, too: they always chirp to report a problem in the middle of the night, or just after you've got the baby to sleep or decided to lay down for a nap. The chirping of the alarm signifies a problem with the system and must be addressed as soon as possible. However, if you cannot get to it right now, the chirping will eventually stop.
The most common reason for a smoke detector to chirp is to signify something is interfering with the proper function of the alarm. This is commonly caused by low battery power or the build-up of dirt or dust over the sensor or in the vent of the smoke detector. Any of these events will cause the smoke detector to chirp, generally once per minute or once every 30 seconds. This chirping will not stop until you address the problem, or until the battery dies completely and the detector can no longer power even the weak warning chirp.
Silence Button Chirping
The other reason for chirping occurs if you press the silence button on the alarm. If your alarm starts going off as a result of simple cooking, a high-humidity shower or another non-emergency reason, your first reaction will likely be to press the silence button, which will shut off the alarm temporarily while you ventilate the area or remove the smoking pan from the stove. Once this button is activated, the alarm will chirp once per minute for 15 minutes to remind you that you have pressed it, that it may have detected an emergency and that you need to address the problem and then reset the alarm.
Actions to Take
If your smoke detector has not stopped chirping, there are a number of actions you should take to silence it. Replace the battery in the detector with a fresh one. Make sure the battery is fully attached in place and installed into the detector so that it touches all the necessary feeds to supply full power to the alarm. If that doesn't work, remove the alarm and use a vacuum cleaner attachment or a can of condensed air to clean the gap between the front cover and the back plate. Clean the front and back as well, paying special attention to the sensor and the vents in the alarm. If these areas become clogged with dust or dirt, the detector will not be able to properly sense an emergency, which is why it is beeping to warn you.
Replacing the Alarm
If nothing you do stops the chirping on the alarm, it may be time to replace it. Most smoke detectors last between five and 10 years, and many are programmed to warn you when it is time to replace them. Your detector should feature a small sticker that indicates when it was installed; consult the sticker to check on the timing.