How to Silence a First Alert 9120B Smoke Alarm

Hunker may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.
Image Credit: IcemanJ/iStock/GettyImages

A properly functioning smoke alarm is literally a lifesaver, but sometimes, these alarms work a little too well and beep, chirp or wail when you're just cooking an extra-smoky meal or when the tool is trying to get your attention for some regular maintenance. Knowing how to quickly silence a First Alert 9120B smoke alarm when there's no present fire danger can save your sanity.


How To Silence a First Alert 9120B Smoke Alarm

Press the Test/Silence button to silence the alarm for 10 minutes. If heavy smoke is present in the area, the alarm will not silence.

9120B Smoke Alarm Sound

You'll know it when you hear it, but just so you're prepared, if your 9120B smoke alarm is activated by smoke, it will sound off with three piercing beeps and then pause and continue with three piercing beeps. This sound pattern repeats on all connected smoke alarms, and the beeps are accompanied by a rapidly flashing red LED light.


Video of the Day

Using the Smoke Alarm Silence Mode

There's little that is more irritating than when you're working your culinary skills in the kitchen and your broiler sends plumes of smoke out of your oven. The smell is offensive, and now you have to deal with the screaming cacophony from the device installed your ceiling.


Don't panic. The First Alert 9120B smoke alarm is extremely easy to silence. After all, there's only one button to press, so it's easy to turn off even when you're rattled.

The one button is the silence/test button. Pressing it once will silence the alarm but only temporarily. Your unwanted alarm will mute for 10 minutes, giving you an opportunity to clear the smoke from the room. If the smoke alarm detects alarm levels of smoke, it will sound off again to alert you to a potentially life-threatening situation. You'll know that your smoke alarm is in temporary silence mode if the red LED light flashes once every 10 seconds.


Silencing Interconnected Smoke Alarms

Some smoke alarm systems are set up for multiple devices to sound throughout the house or facility so everyone knows to evacuate. If multiple interconnected First Alert 9120B smoke alarms are singing their ear-splitting song together when there's no real danger at hand, you can promptly shush all of them.


First, find the original alarm that was offended by smoke and triggered all the other alarms. If you can't tell from the presence of smoke, the original alarm will have a rapidly flashing red LED light. The other alarms will not have a flashing light. Press the test/silence button on this alarm only. All alarms should quiet at this point.

Quieting the Low-Battery Chirp

That periodic but persistent chirping is meant to be maddening and provoke you to take action. If your smoke alarm is letting out a subtle beep once every minute, then it's letting you know that batteries are either low or missing from the device. A smoke alarm without battery backup power could leave you and your family in a dangerous situation when you really need your alarm to function, so change the batteries as soon as you hear this noise.


The latch to open the battery compartment is located on the side of the smoke alarm. Pull the latch with your finger and the battery compartment will swing out. Remove the old batteries and press the test/silence button for 15 seconds. This drains any residual low power from the old batteries. Insert a fresh 9-volt battery, and your fully powered smoke alarm will stop chirping.



Report an Issue

screenshot of the current page

Screenshot loading...