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First Alert

FIRST ALERT BRK SC9120FF Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, 1 pack , White

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Size: 1-Pack


Style: Standard Detection


Pattern Name: SC9120FF


Features

  • Keep your family safe with this hardwired smoke and carbon monoxide alarm; The battery backup means constant monitoring, even if there's a power failure
  • Features an electrochemical carbon monoxide sensing technology as well as an ionization sensor for smoke detection.
  • Indicator lights on the face of the unit display the presence of smoke or carbon monoxide, while an 85 decibel siren provides a clear, loud warning upon detection
  • Can connect to other compatible BRK or First Alert detectors, to ensure all alarms will sound when threat is detected
  • Simple to use, with a single test/silence button, and side load battery compartment; Tamper resistant locking brackets and universal mounting brackets make installation easy
  • Rigorously tested to meet UL standards
  • Faster turnarounds on job sites with the easy-to-install, most-trusted alarms in home safety
  • First Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018)

Description

The BRK SC9120B hardwire combination smoke and carbon monoxide alarm detects two hazards with one simple unit. Carbon monoxide (CO) is a colorless, odorless, deadly gas. It can be emitted by sources including gas or oil furnaces, gas clothes dryers, water heaters, fireplaces, wood stoves, charcoal grills, gas ranges, and space heaters. A clogged chimney, improper venting, and attached garages can also cause carbon monoxide accumulation. The BRK SC9120 hardwire combination smoke and CO alarm with battery backup includes these features: Quick plug in power connector for easy installation, 120 volt AC inter connectable (with maximum 18 compatible devices 12 other compatible smoke alarms + 6 compatible devices like bells, horns, repeaters and door closers. If one unit triggers an alarm, all smoke alarms in the series will sound. Single test/silence button which both silences a non-threatening alarm or low battery warning and allows you to test the unit's functionality. Automatically performs internal test of functionality. Latching alarm indicator which automatically identifies which unit initiated the alarm. Battery drawer lock and mounting bracket lock for tamper resistance. AC power indicator and alarm indicator light. Low battery warning "chirp" and missing battery tab. 9 volt battery backup for peace of mind during power outages. All BRK Electronics carbon monoxide alarms are listed to UL Safety Standard 2034 for residential carbon monoxide alarms. Includes 9 volt backup battery. 10 year limited warranty. Includes: One combination smoke and CO alarm, one 9 volt battery, and user’s manual.Hardwired combination CO smoke alarm features battery backup for constant monitoring.

Brand: First Alert


Style: Standard Detection


Power Source: Battery Powered,Hardwired


Color: White


Product Dimensions: 1.9"D x 5.6"W x 5.6"H


Item Weight: 8 ounces


Alarm: Audible


Operating Humidity: 10-95% RH


Sensor Type: electrochemical,ionization


Global Trade Identification Number: 41


Power Source: Battery Powered,Hardwired


Alarm: Audible


Sensor Type: electrochemical,ionization


Operating Humidity: 10-95% RH


Product Style: Standard Detection


Color: White


Item Dimensions D x W x H: 1.9"D x 5.6"W x 5.6"H


Item Weight: 8 ounces


Brand: First Alert


Model Number: SC9120B


Global Trade Identification Number: 41


Manufacturer Warranty Description: 10 Year Limited


Number of Items: 1


Manufacturer: First Alert


UPC: 029054015341


Mfr Part Number: SC9120B


Unit Count: 1.0 Count


Item Type Name: First Alert BRK SC9120B Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup


Built-In Media: 1-Combination Smoke And Co Alarm, 10-Year Limited Warranty, 9-Volt Backup Battery, User's Manual.


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Jun 22

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Good little detector
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
Works well, and was easy to install. We have them in all rooms.
Reviewed in the United States on April 16, 2026 by Laura Beveridge Harvey
    • Easy to install
Size: 3-Pack Style: Standard Detection Pattern Name: 1040510
So far they are working great. Pretty good value. Easy to install.
Reviewed in the United States on May 8, 2026 by Joseph Phillips
    • Great replacement device
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
This product was ordered to replace a ten year old smoke and carbon monoxide detector. I wanted on that would plug and play without rewiring or creating a new mount. This met all those criteria. Very easy install and smooth operation.
Reviewed in the United States on May 25, 2026 by RickS
    • Good Quality, but here's what I've learned
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
This was a replacement of the same model that was purchased in 2012. A couple of things of note that I think people should know... . CO alarms need to be replaced every so often. I learned this after hearing about a family that perished because of CO even though they had a detector. Quote from Google search on how often to replace, "The detecting components will lose their effectiveness after 5 to 7 years and may no longer detect carbon monoxide. First Alerts website states: “After 5 years any detector should be replaced with a new CO alarm.” COSTAR recommends replacing their CO alarms every 6 years or sooner." . My First Alert started beeping suddenly one day, 3 beeps then a minute or two or maybe three, then 3 beeps, over and over again. Battery wasn't the problem. Came to learn it was the "malfunction" code. I'd had the unit for 5 years already, so gladly replaced it. I am grateful the unit notified us! . Sometimes our detectors have beeps randomly (they are hardwired in our home) and we don't know what's going on - we know it's not a fire or CO because it stops and pauses and starts again. What I've learned is that it's the detector's way of communicating something to us. What I've also learned is that I can never find the darn manual when this happens. So, I have advice... - Best is to keep the manual in a place you'll remember and can get to quickly. If you are like me, once those beeps start, you'll be instantly on edge and won't be in any state to search all over for a manual from years ago. - Second best advice when the unit is giving a message, remove it from the base and look on the back. It actually has beep decipher information written on the back. I do like these First Alert detectors. They are a good quality. However, I do with there was a way to turn the beeps off when it's just a false alarm (kids burning too much incense, for example). ... show more
Reviewed in the United States on January 14, 2018 by imaginera
    • Great buy!!!!
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
I assumed these would be from old stock, since they were less than half the cost of the home centers. But, to my surprise they were not. Purchased April 2026, manufactured February 2026. Awesome!!!!! Plug and play as well!!!
Reviewed in the United States on April 23, 2026 by Behatchi The Tooler
    • Works well
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
I was hoping for a plug in replacement but that didn't happen. That being said, wire nuts are easy as well as replacing the mounting bracket. It does work with my other existing alarms and seems to work well so I'm happy.
Reviewed in the United States on May 1, 2026 by Michael
    • BRK Smoke and CO detector Replacement
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
Easy to install as a replacement.
Reviewed in the United States on June 3, 2026 by Delia Allen
    • Works great
Size: 1-Pack Style: Standard Detection Pattern Name: SC9120FF
They work perfectly
Reviewed in the United States on June 7, 2026 by Steven Tortu

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