Hard wired smoke alarms typically have LED lights which help with the diagnostics. For models with green and red lights: green means it is working properly, red means it is not.
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.
Typically, a smoke alarm has a red and green light to allow you to understand the system is working properly. However, there are other models that will integrate a third light indicator to separate when a malfunction, power source, and a simple battery replacement might be needed.
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.
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 detector or alarm has a blinking or steady light with no audible alarm sound, this typically indicates that the unit is receiving power. The color of the LED light and the blinking pattern may differ based on the model you own.
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.
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.
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.
You can also use real smoke to test the smoke sensor. To do this, light two or three matches, and hold them together a few feet underneath the detector. The smoke from the matches should cause the alarm to sound if the detector is functioning properly. If it doesn't sound, replace the detector immediately.
On the bottom of the smoke alarm is a reset button, press it!
Test your alarm whether it is battery powered or hard-wired by pressing the button on your smoke alarm and keeping it pressed down. The alarm should sound. If your alarm has no button, it is outdated and must be replaced.
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.
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.
How long do hardwired smoke alarms last? If you're aiming for the longest dependable smoke alarm coverage, hardwired alarms can easily offer 10 years of protection, in fact every alarm must be replaced every 10 years.
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.
It's a sound many homeowners have heard: the 3 a.m. alarm chirp. Why does it happen? Well, it's a simple matter of the battery's charge level and a home's air temperature. As a smoke alarm's battery nears the end of its life, the amount of power it produces causes an internal resistance.
How to maintain and when to replace. Like coupons and canned goods, smoke alarms have an expiration date. "They have a life of 10 years," Roux says. "But, if it has a built-in CO detector, you'll need to replace it sooner." According to Consumer Reports, most CO detectors come with a five- to seven-year warranty.
Every month: Smoke alarms should be tested (by pressing the test button) to ensure the battery and the alarm work. Every six months: Smoke alarms should be cleaned with a vacuum cleaner. This will remove any dust or particles that could prevent the smoke alarm from working properly.
Smoke alarms sound for all sorts of reasons—beyond actual fires, that is: Dust or other debris on the sensor. Spiders or insects taking refuge inside the alarm (Ugh) Humidity, including steam from your shower (And you thought a middle-of-the-night malfunction was bad!)
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.
Artwork: How an optical smoke detector works. But if a fire breaks out, smoke enters the chamber (6) and scatters some of the light beam (7) into the photocell (3). This triggers the circuit (8), setting off the shrill and nasty alarm (9) that wakes you up and saves your life.