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. Pressing the Test button is the only recommended method.
The lack of the green light means that there is no power to the unit. Check that the fuse is back on. If it is then you need the electrician to sort out your wiring. The alarm might have been fitted to the part of the lighting system that is switched.
Blinking Red Light: Usually means the smoke detector is working properly and is in standby mode. Steady Red Light: Often indicates that the alarm is sounding or that there is an issue (like a low battery or a malfunction). Green Light: Typically indicates that the smoke detector is powered and functioning properly.
Open it up. If there is a battery or batteries, remove them. If it stops working, it's battery powered. If it still works, it is hardwired with a battery backup. If there are no batteries, consider replacing it. You don't want to die in a fire because it happened when the power was out.
"Replace all smoke alarms, including those that use ten-year batteries and hard-wired alarms, when they are ten years old or sooner if they don't respond properly when tested." Each smoke detector should be replaced 10 years after the date of installation.
For some units, a green light flashing every 5 seconds signifies that the device is in “battery only” mode, powered by AC. When the detector senses a smoke or carbon monoxide hazard, the green light might become steady, whereas in “hush” mode, it may flash every 2 seconds.
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.
They are usually mounted in a high position located in the living room, hallway or bedrooms. You will notice two different lights on your smoke alarm: A steady green light shows the alarm is being powered. A red light that flashes once a minute shows the alarm is working.
If you do not see the red light flashing, change the batteries in the alarm immediately.
Here are some examples of why smoke detectors periodically have a flashing red or green LED light without an alarm sounding; To indicate that the alarm is receiving power and is operating normally. An end-of-life or low-battery warning. To indicate the alarm is in hush mode or that there is a fault with the alarm.
The green light on my smoke alarm has gone out, what does this mean? The AC power has been interrupted. Check the circuit breaker and AC wiring to correct the problem.
Can I install a hardwired smoke detector myself? While it is technically possible, it is not recommended. Working with your home's electrical system can be dangerous and complex, best left to a qualified electrician.
Smoke detectors last up to 10 years, at which point it's best to replace them for your safety. Replace smoke detectors that chirp constantly, fail a test, go off for no reason, or have been recalled.
Test it! Push the test button on the front of the unit and it should emit a loud beeping sound for as long as the button is depressed. If you have a smoke alarm with batteries: Smoke Alarms powered by long-lasting batteries are designed to replace the entire unit according to manufacturer's instructions.
Many smoke detectors use an LED light to show you that everything's working properly. If your device's on/off button has a stale red light, it likely means the system is working properly. Some detectors will even use a light that flashes periodically to tell you they're working.
Green Light: The green LED will be lit continuously or flash every 30 seconds to indicate the unit is operating properly. In Hush® mode the LED blinks every 2 seconds and once per second if it is the initiating alarm.
Hard Wired
There are two LED lights on the top of the unit. One light will be solid green, this indicates that the alarm is hardwired and working. The second LED flashes red every 48 seconds, which indicates normal operation.
Why did my fire alarm randomly go off in the middle of the night? This is likely due to one of the common causes like low battery, dirt buildup, humidity, or insects interfering with the sensor.
The batteries are low: A blinking red light, usually accompanied by a loud beep, could mean the batteries in the unit are low. Consider adding fresh batteries and testing to ensure they're working. You need to replace it: Smoke detectors don't last forever.
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.