Try a manual reset.
Remove the batteries and hold down the reset button for 15 to 20 seconds. Reconnect the batteries and alarm. It will most likely beep once as evidence it is working, then it should stop.
Even after the battery has died, the detector maintains a residual charge that will keep the chirp going for at least seven days. To get the device to stop chirping once the battery has been removed, you must drain this residual charge by holding the test button for 15 seconds.
Newer smoke alarms keep some errors in the processor. The smoke alarm must clear errors after the battery is changed, but it might continue to chirp even after you change the batteries. This usually occurs in electrical powered smoke alarms with a battery backup.
Most battery powered smoke detectors will beep for a minimum of 30 days before the battery dies. You'll know the battery is losing charge if you hear consistent beeping every 30 to 60 seconds.
Consistent Chirping
If a smoke alarm is chirping consistently, one of the following may be the reason: The battery may need to be replaced. An alarm will chirp every 30 to 60 seconds for a minimum of seven days. With a "low battery" announcement, disconnect the unit and replace the batteries.
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.
The "HUSH" feature has the capability to temporarily desensitize the smoke alarm circuit for approximately 7 minutes. This feature is to be used only when a known alarm condition, such as smoke from cooking, activates the alarm. The smoke alarm is desensitized by pushing the "HUSH" button on the smoke alarm cover.
The only way to tell is to put your ear next to it and listen for the chirp. The smoke alarm, furnace alarm, or carbon monoxide alarm alarm is chirping every 30 seconds or so, but it's hard to tell which direction the sound is coming from.
Reset Your Smoke Alarm
Unmount the alarm and disconnect the power cable connected to it. Remove the battery, press the test button for 15 seconds. An alarm will sound briefly, then the alarm will silence. Reinsert the battery, reconnect the power cable and put the smoke detector back on its mounting bracket.
Many carbon monoxide and smoke detectors come with a “Hush” feature, which will stop the beeping for 72 hours. To silence the beeping, press and hold the “Hush” or “Test” button. The system will chirp to let you know the command is accepted, and you will have 72 before it begins again.
What does it mean? This is the power indicator light: First Alert and BRK alarms have a power indicator light to show you that your alarm is receiving power. Some alarms have a red or green light that blinks every few minutes, while other models blink rapidly or shine a solid light.
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.
Many people consider it a difficult job to do. Most people ask themselves, “can I remove a hardwired smoke detector?” The answer is you can！ If you have to stop the hard-wired smoke detectors from beeping, you must unplug them from the clip and remove the battery.
Part 2 of 3: Installing a New Battery for Wired Detectors. Turn off power to your wired smoke detector. Wired smoke detectors are connected directly into the power supply of your house, which is sometimes also called the mains.
Battery smoke detectors run solely on batteries. Hardwired smoke detectors run on electricity, but they also have a backup battery for power outages. When you hear a hard-wired smoke detector beeping, it means you need to replace its battery.
A solid green light on your smoke detector indicates that the device is on and operating normally.
A: Beeping or chirping smoke detectors are about as annoying as it gets. You might already know that a chirp every 30 to 60 seconds indicates a low battery, so you'll quickly attend to changing it. This typically solves the problem, whether the alarm runs entirely on batteries or is hardwired with a battery backup.
For most residential smoke detectors, blinks are common; you need to be conversant with the colors showing. Different smoke alarms use the green and red LED to indicate the device's power status such that a flashing green means low battery while a constant blink means AC power is connected.
The mains powered smoke alarms have a green indicator. Smoke Alarms have a red light that goes off every 40 to 60 seconds to tell you if they're working. When the smoke alarm is activated, the red light flashes continuously.