BRK First Alert - SC9120B Smoke & Carbon Monoxide Alarm, Hardwired, 9V Battery

$ 49.99
Availability: In Stock

Alarm Type Smoke & Carbon Monoxide
Power Source Hardwired
Ionization & Electrochemical
Interconnects Yes
Battery 9V 

Braeburn Digital Thermostat
Programmable wi fi thermostat
Affordable wifi thermostat

The first alert SC9120B combination smoke/carbon monoxide alarm is perfect for protecting your family against the dangers of fast-burning fires. Hardwired directly into your home’s electrical system, this model also comes with a backup, 9V battery intended to provide emergency power in the event of power outages. The BRK SC9120B harnesses the power of the most accurate electrochemical carbon monoxide sensor, and combines that with best-in-class ionization technology.

As a leading choice for accurate carbon monoxide and wired smoke alarm, the SC9120B provides the most optimal protection. Due to its Intelligent Sensing Technology, this first alert fire alarm reduces the frequency of nuisance alarms and comes with silencing options to quiet both low-battery chirps and unwanted alarms.

The SC9120B first alert model comes with easy, quick, and cost-effective installation and mounting. With a large opening and keyhole slots in the mounting bracket, access to the alarm’s wiring is quick while fully eliminating the need to remove the electrical box screws. Dual locking mechanisms ensure theft prevention, and power connection is made easy through a “Quick-Connect” wiring harness. As with all BRK alarms, this model comes with a guaranteed 10-year warranty.


  • Electrochemical Carbon Monoxide Sensor - the most accurate sensor available as compared to other sensing technologies
  • 9V Alkaline Battery Backup
  • Latching alarm indicator - remembers which unit initiated an alarm
  • Two silence features - can silence the low-battery chirp for up to eight hours or temporarily silence an unwanted nuisance alarm
  • End of Life Signal provides audible notification alarms needs to be replaced
  • Intelligent Sensing TechnologyTM helps reduce the number of nuisance alarms
  • Operating Current .09 amps (standby/alarm)
  • Temperature Range 40 degrees F (4 degrees C) to 100 degrees F (38 degrees C)
  • Humidity Range 10% to 95% relative humidity (RH)
  • Audio Alarm 85dB at 10 feet
  • Perfect Mount - allows for easy alignment of alarm
  • Dust Cover
  • 10-Years Limited Warranty
  • Indicator Lights/Sounds
  • AC Power: Constant Green LED
  • DC Power: Intermittent Green LED
  • Local Alarm: Red LED flashes rapidly
  • Remote Alarm: Red LED out Latching Alarm: Red LED flashes every 5 seconds after local alarm stops
  • Listing UL217 & UL 2034 Standards
  • Dimension 5.58" dia x 1.97"H

Easy Installation/Maintenance - First Alert SC9120B carbon monoxide alarm & smoke detector Preferred features include a large opening in the mounting bracket for easy access to wiring. Keyhole slots in the mounting bracket eliminate the need to remove the electrical box screws for installation. A battery pull tab keeps the battery fresh until the home is occupied. Battery installation and removal can occur while the unit is mounted to the ceiling or wall via the side load battery compartment. Two locking features are provided to prevent battery theft and/or theft of the unit. Connection to AC power is made with a "Quick-Connect" wiring harness. Installation is quick, easy and cost-effective.

All BRK Electronics smoke alarms meet UL 217 standard and are listed with the California State Fire Marshal. They use the new UL mandated repeating 85-decibel alarm horn pattern. 10-year limited warranty. For a full list of states and cities requiring 10 Year alarms click here.

Don't know what type of smoke and carbon monoxide alarm is right for your home? Check out our guide on how to choose the right smoke detector for your home

Info and Guides