Why is my First Alert smoke and carbon monoxide alarm not light?

Author: Ms. Cristal Schoen  |  Last update: Saturday, February 21, 2026

A loose battery cannot power the smoke alarm properly. Your AC power may not be on. Hardwired units will have a power indicator light (red or green) that shines continuously when they are receiving electrical power. If you have a 10-Year model, the smoke alarm may not have been properly activated.

Why is my First Alert smoke alarm not lighting?

If the green power indicator light does not light, TURN OFF POWER TO THE JUNCTION BOX and recheck all connections. If all connections are correct and the green power indicator still does not light when you restore the power, the unit should be replaced immediately.

Why is there no green light on my carbon monoxide detector?

If green light is not on its not getting power from the wire. Something is probably mis wired.

Why is there no green light on my smoke 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.

Should there be a light on the carbon monoxide alarm?

The green, red & amber lights will immediately flash in sequence to show they are working - this is normal. Install the Carbon Monoxide Alarm (CO Alarm) in every room that contains a fuel burning appliance, particularly rooms where people spend a lot of time e.g. bedrooms, kitchens and sitting rooms.

Smoke Alarm - What The Lights Mean

What does solid red light on first alert smoke detector mean?

Look for the detector that has a solid red LED light. That means it is the detector that is in alarm condition. Once you find it, remove that detector by unplugging the power to it and take the batteries out.

Should there be a green light on my first alert smoke detector?

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.

Should a smoke detector have a light?

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.

What to do if a carbon monoxide alarm goes off?

If the alarm sounds, vacate the house. Then, it's best to call 911 or the fire department to come out and test for the source of carbon monoxide. Once they've identified what is causing carbon monoxide to be released in your home, you'll need to contact a licensed professional to service the offending appliance.

What color should the light be on the first alert carbon monoxide detector?

First Alert CO600 Plug-In Carbon Monoxide Detector

A: That is the power light. It is normally solid red and flashes when there is a problem.

What if carbon monoxide alarm goes off but no fire?

Your carbon monoxide alarm is going off for one of the following reasons: It is doing its job properly and detects CO pollution in the air. It is a false alarm caused by other household items. The detector is malfunctioning or the batteries need changing.

How can I be sure my carbon monoxide detector is working?

How to test your carbon monoxide detectors to ensure they are working properly? To test your carbon monoxide detectors, press and hold the test button on the alarm. The detector will sound 4 beeps, a pause, then 4 beeps for 5-6 seconds. Refer to the user manual for your specific model.

How do I reset my First Alert smoke and carbon monoxide alarm?

Remove the alarm from your ceiling or wall. Open the cover and take out the battery. Press and hold the test button for 15-30 seconds. This will fully reset the smoke alarm and drain any charge left inside.

Does the first alert smoke alarm detect carbon monoxide?

First Alert's Precision Detection Advanced Sensing Technology. Voice & Location Alerts for Danger and Helps Escape Safely. Provides Reliable 2-in-1 Protection Against Both Smoke and Carbon Monoxide.

Do First Alert smoke detectors go bad?

If your alarm is more than 10 years old, it's time for a replacement. Note: First Alert's Smoke / CO Warranty begins at the initial date of retail purchase--not the date of manufacture.

Why is there no green light on my smoke detector?

Generally, a solid green light on your smoke detector means that it's working properly. If the green light goes off, you know that there's no power going to the system. As mentioned, a solid green light can also mean that your detector has finished its power upcycle.

What color should my smoke detector blink?

It's Working Properly: Some brands use an occasional red blinking light to indicate the unit is working properly.

How do you know if a hard-wired smoke detector is bad?

If your smoke detectors are yellowing, chirping non-stop, or going off unexpectedly, it's time to call in our electrical pros from Integrity Home Solutions. We can inspect and replace hardwired smoke detectors or install them if you don't have them in place already. Don't take a chance on your family's safety.

How to tell if the first alert smoke detector is working?

Push and hold test button until the alarm sounds: 3 beeps, pause, 3 beeps, pause. If the unit does not alarm during testing, DO NOT lock the battery compartment! Install a new battery and test again. If the Smoke Alarm still does not alarm, replace it immediately.

What is the difference between a steady green and a blinking green smoke alarm?

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.

What is the difference between red and green light on First Alert smoke and carbon monoxide alarm?

The green light is a power indicator. If you have a steady green, you have constant power. The red light a peeping sound is probably a low battery indicator. Detectors normally do not sound unless their battery is low.

What does 3 beeps mean on a First Alert smoke and carbon monoxide detector?

1 beep every minute: This means that the alarm has low batteries and you should replace them. 3 beeps every minute: This means the alarm has encountered a malfunction and needs replacement. 5 beeps every minute: This means your alarm has reached the end of its life and needs to be replaced with a new alarm.

What does a solid red light mean on a carbon monoxide detector?

Luckily, if your First Alert carbon monoxide alarm is holding a steady red light, this means that it is operating normally.

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