How to Tell If Your Smoke Alarm is Working. Hardwired units will have a steady green LED light to show that it's receiving AC power. Battery-operated units will have a quick flash every 30-45 seconds. This does not necessarily mean the alarm is working.
Why is the green power light flashing on my First Alert® plug-in Carbon Monoxide Alarm? A flashing green light is a normal part of the power up cycle. Any time there is a power outage, brownout, surge or other problem with the power, the alarm goes through a power up cycle.
Some alarms have a red or green light that blinks every few minutes, while other models blink rapidly or shine a solid light. The light isn't a cause for concern unless the alarm is also beeping or chirping.
Low Battery
As the battery in a smoke alarm gets weak, the smoke alarm will “chirp” about once a minute to let you know that the battery needs to be replaced. Note: Only the device with a low battery will chirp. The other interconnected alarms should be silent.
Red LED Indicator: The red LED will blink in conjunction with the alarm sound. Therefore, the red LED will blink during a smoke alarm, a low battery mode chirp, a unit error mode chirp or at end of unit life.
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.
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.
If the carbon monoxide concentration in the air is much higher, signs of poisoning may occur within 1-2 hours. A very high carbon monoxide concentration can even kill an exposed individual within 5 minutes.
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. Common causes of smoke detector false positives around the house.
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.
A smoke detector blinking red could mean: It's Working Properly: Some brands use an occasional red blinking light to indicate the unit is working properly.
Dust, Dirt and Environmental Smoke
Dust and dirt that comes from activities like remodeling may set off your smoke alarms. To clean your smoke alarm, open it up carefully, and look inside for dust or dirt. Use a vacuum attachment or electronic aerosol cleaner to remove dust particles.
Resetting a hardwired unit with a removable battery backup
Remove the battery (for a sealed-battery model, see Battery Settings for a 10-Year Alarm to learn more). Press and hold the test button for five seconds. Reconnect the power and reinstall the battery.
On First Alert carbon monoxide alarms, the red light flashes to show the CO alarm is properly receiving battery power. If you do not see the red light flashing, change the batteries in the alarm immediately.
Smoke alarms need replacing after ten years. In all cases of nuisance beeping or false alarms do not disconnect your alarm or leave the alarm without batteries fitted.
Maintain your alarms
Test smoke alarms every month by pressing their test buttons. 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.
Testing and Changing Your Fire Alarm Battery
If your smoke alarms are powered by a nine-volt battery, the battery should be replaced every 6 months, while the alarm itself should be replaced once every 10 years. For 10-year lithium-powered fire detectors, you won't need to replace the battery.
Testing and Changing Your Smoke Alarm Batteries
If your detector is hardwired into your home's electrical system, replace the backup battery at least every 6 months and replace the smoke detector itself at least every 10 years.
Helpful? A: The AA Battery is guaranteed to power a Kidde smoke alarm or carbon monoxide alarm for no less than 2 years or we will replace the batteries. The batteries must be installed in the Kidde alarm within one year of both the date of purchase of the batteries and the date of manufacture of the Kidde alarm.