BRK Hardwired Interconnected Smoke Alarm with Battery Backup-9120B - The Home Depot


Model # 9120B

Internet # 100065881

Hardwired Interconnected Smoke Alarm with Battery Backup

BRK Hardwired Interconnected Smoke Alarm with Battery Backup

This item has been discontinued.
The Home Depot no longer carries this specific product.

$14.97 / each


Model # 9120B

Internet # 100065881

The BRK 9120B 120-Volt AC Smoke Alarm with Battery Backup is designed to install faster, perform better, and be even smarter than before. This alarm is 120-volt AC inter-connectable (with maximum 18 compatible devices), which lets the alarm be interconnected with up to 12 other compatible smoke alarms and six compatible devices like bells, horns, repeaters, and door closers to network a comprehensive system for your home. If one unit triggers an alarm, all smoke alarms in the series will sound. The 9120B includes an ionization sensor which helps detect fast flaming fires that consume combustible materials rapidly. The dust-reducing packaging helps avoid accidental alarms due to contaminants and the 85 dB horn can be inspected with a test button. This unit includes a quick-connect wiring harness for easier installation to your household current and 9-volt battery backup ensures protection even during power outages or service interruptions. 10-year limited warranty.

  • 120V AC Smoke Alarm with Battery Backup
  • 85 dB horn sounds as smoke reaches dangerous levels
  • Can be interconnected with 12 additional BRK and First Alert Smoke Alarms and 6 compatible devices such as heat alarms for a complete safety system
  • Dust-blocking covers to reduce nuisance alarms associated with particulate contamination
  • Locking pins deter removal
  • A single button tests units functionality and silences nuisance alarms
  • 9-volt battery backup ensures operation during household current interruption
  • Power indicator lets you see at a glance that the alarm is powered
  • Universal mounting bracket with wide opening for easy wire access
  • Meets UL standards

Info & Guides

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Assembled Depth (in.)  2 in  Assembled Height (in.)  5.63 in 
Assembled Width (in.)  5.5 in 
Alarm Sensor Type  Ionization  Alarm Type  Smoke 
Alarm/Detector Features  No Additional Features  Battery Back-Up  Yes 
Battery Power Type  Alkaline  Battery Size  9-volt 
Commercial / Residential  Commercial / Residential  Connector/Contact Type  4-Wire 
Electrical Product Type  Smoke Detector  Hazardous Code  null 
Included  Batteries  Power Source  Hardwired 
Returnable  90-Day  Voltage (volts)  120 
Warranty / Certifications
Certifications and Listings  1-UL Listed 


Rated 4.0 out of 5 by 59 reviewers.
Rated 5.0 out of 5.0 by Easy to install We bought two to replace older hard wired smoke alarms. Clear instructions and a very easy installation. They're new so we can't comment yet on their longevity nor performance. December 31, 2013
Rated 1.0 out of 5.0 by Run away! This brand is the worst. Cheap and used by builders simply to pass inspection. Battery doors stick and are difficult to open and close. If one battery goes out, they all have to be replaced. They eat batteries like candy. I replace routinely when the time changes twice per year, yet inevitably have to add one or two additional changes each year. Since they are interconnected they all scream at the same time. You get one single chirp to alert you to a battery fail, but they all chirp, so you don't know which one really needs changing. If not changed immediately all will blare incessantly until new batterie are added. I have six, so this gets expensive. For some reason, they are the most active during sleeping hours. For the second time in less than a week the entire household has been kept awake all night after batteries were just changed. I just took down all of them. Something that should have been done a long time ago. Also note that despite what the description and the package and the unit say, there is no test or silence function. None. Trust me, buy something else unless you enjoy sleepless nights and buying batteries in bulk. If you don't have a Costco or Sam's or BJ's membership, get one. It's the only way you can afford the batteries. This company should go out of business. November 19, 2014
Rated 5.0 out of 5.0 by Performs as advertised We installed a combination of fifteen interconnected hard-wire and wireless smokes along with three interconnected wireless CO detectors. All eighteen linked together just as advertised and worked flawlessly. Here's to hoping we never need them but if we do, then we can sleep comfortably knowing we're well protected. October 15, 2013
Rated 5.0 out of 5.0 by BRK 9120B Bought our home new in 1999. The smoke alarms installed at that time were BRK 4150B. After 12 years they started to chirp even when new batteries were installed. I have read where dust will make any smoke alarm defective over time. So I replaced all 8 of them with the new BRK 9120B which has the battery backup and which used the same plug, but different base plate. It took me only 30 min to install all 8 of these smoke alarms. I tested them all and they all work perfectly. I then tested with a napkin on fire to see if all 8 of would go off at the same time and they did. I am a happy camper and easy install. February 6, 2014
Rated 5.0 out of 5.0 by Replacing builder-installed smoke detectors Install was easy and they replaced the wired-in models our home came with, as promised. January 18, 2015
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