Hardwired Combination Carbon Monoxide and Smoke alarm with Battery Back-Up, and interconnectivity with First Alert® Alarms

This Hardwired combination carbon monoxide and smoke alarm contains both ionization and electrochemical sensors. The SC9120BCNA features battery backup for full protection during power outages, an adapter for easy replacement of other branded alarms and a mute/silence button to quiet false alarms. The alarm is also equipped with an easy access battery drawer allowing batteries to be changed without removing the alarm from the ceiling. 5-year limited warranty.


First Alert® hardwired smoke detectors are alarms wired directly into your homes electrical system and include battery backup and mute button. Hard-wired smoke detectors with battery backup ensure that alarms work even during power outages. Hardwired alarms can integrate with up to 12 other First Alert® or BRK™ brand wired alarms.





  • Kitchen
  • Living Room
  • Basement
  • Bedroom
  • Hallway
  • Indoors
  • 2 in 1 Protection, Ionization and Electrochemical Sensors
  • Battery backup - For Protection During Power Outages
  • Mute/Silence Button
  • Easy access battery door
  • Optional theft-prevention lock protects the detector
  • Easy Plug Wiring Adapter
  • Loud 85db Siren
  • 9V Backup Battery Included
  • 7-Year Limited Warranty
Warranty Claim7-Year Limited
SensorElectrochemical & Ionization