The most likely reason smoke detectors go off unexpectedly is that people aren't changing the batteries in them often enough. In most sensors you might think of, the strength of the signal goes up when they detect what they're supposed to.
This battery characteristic can cause a smoke alarm to enter the low battery chirp mode when air temperatures drop. Most homes are the coolest between 2 a.m. and 6 a.m. That's why the alarm may sound a low-battery chirp in the middle of the night, and then stop when the home warms up a few degrees.
In conclusion, the smoke detector may still be beeping even after the battery is changed because the battery may be low, the smoke detector may be faulty, or there may be dust or other particles in the smoke detector.
Some smoke alarms also double as carbon monoxide detectors. When it gets cold outside, it's normal for people to crank up the heat. Furnaces, space heaters, fireplaces — these are some solutions to warming up a home.
First, try the reset button on each smoke alarm. If that doesn't work, flipping the circuit breaker off and back on might stop the noise. If all of that fails, your ultimate solution may be to disconnect the smoke alarms and remove their batteries one by one.
Your alarm manufacturer may have included a blinking red light to let you know it's time to test the alarm again. The Batteries are Low: Usually accompanied by a loud beep, a blinking red light could mean the batteries in the unit are low. Consider adding fresh batteries and running a test to make sure it's working.
Power interruptions are common in areas where utility companies switch grids in the early hours of the morning. In AC or AC/DC smoke alarms, a loose hot wire connection can intermittently disconnect power to the smoke alarm. The effect is the same as a power failure. When power is restored, the units may alarm briefly.
Check for a Fire
If your smoke alarm won't stop going off, reset the alarm after first checking that there is no actual fire in your home.
If you have changed the batteries and tried the circuit breaker, but the beeping persists, you may need to try resetting the detector(s): Use the reset button: most smoke detectors have a red reset button. Hold the reset button down for approximately 15-20 seconds.
A carbon monoxide detector is a must for any home and just as important as a smoke detector. CO detectors should be placed near all bedrooms; they're the only way you will know if carbon monoxide is affecting the air quality in your home, and can help prevent serious illness and even death.
Here's a simple guide: Smoke alarms alert you with three beeps in a row. Carbon monoxide alarms alert you with four beeps. A single chirp means the battery is low or the detector should be replaced.
Phantom fire alarms? You might have a spider problem. Is your smoke alarm going off even though there's no smoke or fire to trigger it? If you open the smoke detector (or have someone else do it), you might find the culprit: spiders!
Humidity in the air is prone to set off a false alarm. Steam from the shower is visible to the naked eye, meaning it's even more likely to trigger your smoke alarm.
It's time to change the battery
Low batteries are the most common reason smoke detectors beep or send a trouble signal to your security panel, when there is no smoke or fire. As the battery weakens, the device will beep regularly to let you know it's time to replace it.
Press and hold the test button on the smoke detector. It can take a few seconds to begin, but a loud, ear-piercing siren should emanate from the smoke detector while the button is pressed. If the sound is weak or nonexistent, replace your batteries.
If your alarms use regular batteries, swap in fresh batteries at least once a year. A “chirping” sound means that it's time to change batteries. Because alarm sensors wear out, replace each alarm at least every 10 years. Also, alarms have labels showing when they were made.
Smoke detector shows steady green light – no alarm
Battery and electrical power smoke detectors will usually have a steady green light to let you know the detector has electrical power and is in working order.