Shop replacing brk 4120b smoke detector

Sponsored
About our ads
$13.38
BRK Electronics First Alert 4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
11
$13.38
BRK Electronics First Alert 4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
11
$54.99
$92.99
First Alert BRK SC-9120B Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup
Amazon.com
3K+
Free shipping
40% off
$54.99
$92.99
First Alert BRK SC-9120B Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup
Amazon.com
3K+
$13.38
First Alert BRK SA4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
235
$13.38
First Alert BRK SA4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
235
$117.04
$209.99
FIRST ALERT BRK SC9120B-3 Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup, White, Pack Of 3
Amazon.com
25K+
Free shipping
44% off
$117.04
$209.99
FIRST ALERT BRK SC9120B-3 Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup, White, Pack Of 3
Amazon.com
25K+
$13.38
BRK Electronics First Alert 9120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
6
$13.38
BRK Electronics First Alert 9120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
6
$18.99
Sunco First Alert BRK Hardwired Ionization Smoke Alarm
Sunco
$18.99
Sunco First Alert BRK Hardwired Ionization Smoke Alarm
Sunco
$20.61
First Alert BRK Sc9120b (2 Pack) Smoke U0026 Carbon Monoxide Detector W/ Batt Backup
kreaagency
$20.61
First Alert BRK Sc9120b (2 Pack) Smoke U0026 Carbon Monoxide Detector W/ Batt Backup
kreaagency
$319.99
BRK Hard-Wired W/Battery Back-Up Photoelectric Smoke And Carbon Monoxide Detector W/Voice 6 Pk
Ace Hardware
$319.99
BRK Hard-Wired W/Battery Back-Up Photoelectric Smoke And Carbon Monoxide Detector W/Voice 6 Pk
Ace Hardware
$19.73
First Alert BRK SC9120LBL Hardwired Smoke And Carbon Monoxide (CO) Detector With 10 Year Sealed Battery Backup , White Pack Of 2
alertakey
$19.73
First Alert BRK SC9120LBL Hardwired Smoke And Carbon Monoxide (CO) Detector With 10 Year Sealed Battery Backup , White Pack Of 2
alertakey
$18.44
X-Sense Hardwired Combination Smoke And Carbon Monoxide Detector, Hardwired Interconnected Smoke And CO Detector Alarm With Replaceable Battery Backup, XP04
alertakey
$18.44
X-Sense Hardwired Combination Smoke And Carbon Monoxide Detector, Hardwired Interconnected Smoke And CO Detector Alarm With Replaceable Battery Backup, XP04
alertakey
$54.99
BRK SMICO105-AC Smoke & CO Alarm - Hardwired With Ionization Sensor With 10 Years Battery Backup
WholesaleHome
8
$54.99
BRK SMICO105-AC Smoke & CO Alarm - Hardwired With Ionization Sensor With 10 Years Battery Backup
WholesaleHome
8
$189.99
BRK SMI105-AC Hard-Wired W/Battery Back-Up Ionization Smoke Detector 6 Pk
Ace Hardware
$189.99
BRK SMI105-AC Hard-Wired W/Battery Back-Up Ionization Smoke Detector 6 Pk
Ace Hardware
$38.20
BRK Smoke Alarm: Smoke, Hardwired, Battery Backup, Smoke Detector, Ionization, Hardwired, 10 Yr Model: SMI105-AC
Grainger
32
$38.20
BRK Smoke Alarm: Smoke, Hardwired, Battery Backup, Smoke Detector, Ionization, Hardwired, 10 Yr Model: SMI105-AC
Grainger
32
$13.56
BRK 1046836 SMI100-AC Interconnectable Ion Smoke Alarm W/ Battery Backup | Supplyhouse.Com
SupplyHouse.com
21
$13.56
BRK 1046836 SMI100-AC Interconnectable Ion Smoke Alarm W/ Battery Backup | Supplyhouse.Com
SupplyHouse.com
21
$45.95
BRK 3V Battery-Operated Photoelectric Smoke Alarm - 10-Year Backup Battery - LS-SM210BRK
All Hands Fire Equipment
$45.95
BRK 3V Battery-Operated Photoelectric Smoke Alarm - 10-Year Backup Battery - LS-SM210BRK
All Hands Fire Equipment
$762.85
BRK Smoke/CO Alarm: Carbon Monoxide/Smoke, Hardwired, Battery Backup, Smoke/CO Detector, Hardwired [PK/6] Model: SMCO100V-AC
Grainger
$762.85
BRK Smoke/CO Alarm: Carbon Monoxide/Smoke, Hardwired, Battery Backup, Smoke/CO Detector, Hardwired [PK/6] Model: SMCO100V-AC
Grainger
$79.95
First Alert Brk Interconnect Hardwired Smoke Co Alarm Battery Voice
eBay
$79.95
First Alert Brk Interconnect Hardwired Smoke Co Alarm Battery Voice
eBay
$51.95
BRK Hard-Wired Photoelectric Smoke Alarm - 2X AA Backup Battery & Voice Alert - LS-SM100VACBRK
All Hands Fire Equipment
$51.95
BRK Hard-Wired Photoelectric Smoke Alarm - 2X AA Backup Battery & Voice Alert - LS-SM100VACBRK
All Hands Fire Equipment
$159.95
First Alert BRK Sc9120b (2 Pack) Smoke & Carbon Monoxide Detector W/ Batt Backup
Walmart
Free shipping
$159.95
First Alert BRK Sc9120b (2 Pack) Smoke & Carbon Monoxide Detector W/ Batt Backup
Walmart
Free shipping
$37.99
BRK Voice And Locatio Hard-Wired W/Battery Back-Up Photoelectric Smoke Detector 1 Pk
Ace Hardware
21
$37.99
BRK Voice And Locatio Hard-Wired W/Battery Back-Up Photoelectric Smoke Detector 1 Pk
Ace Hardware
21
$39.79
Onelink Smoke Alarm, 120V AC, Hardwired, White By BRK-First Alert SA520B
Electrical Parts
3
$39.79
Onelink Smoke Alarm, 120V AC, Hardwired, White By BRK-First Alert SA520B
Electrical Parts
3
$24.99
$29.00
Brk Hard-Wired W/Battery Back-Up Ionization Smoke Detector
Walmart
79
Free shipping
13% off
$24.99
$29.00
Brk Hard-Wired W/Battery Back-Up Ionization Smoke Detector
Walmart
79
$329.99
Sunco 6-Pack First Alert BRK SMICO100-AC Interconnect Hardwire Smoke And Carbon Monoxide Alarm
Sunco
26K+
$329.99
Sunco 6-Pack First Alert BRK SMICO100-AC Interconnect Hardwire Smoke And Carbon Monoxide Alarm
Sunco
26K+
$19.99
BRK First Alert - FG250B Dual Ionization Smoke Alarm With 9-Volt Battery
WholesaleHome
$19.99
BRK First Alert - FG250B Dual Ionization Smoke Alarm With 9-Volt Battery
WholesaleHome
$40.40
First Alert Brk Battery-Operated Smoke Alarm FG250LB
DkHardware.com
4
$40.40
First Alert Brk Battery-Operated Smoke Alarm FG250LB
DkHardware.com
4
$23.96
$29.95
Brk Smi105-Ac First Alert Ac Powered Hardwire Smoke Alarm 1046850
eBay
2
Free shipping
20% off
$23.96
$29.95
Brk Smi105-Ac First Alert Ac Powered Hardwire Smoke Alarm 1046850
eBay
2
$58.13
BRK Smoke Alarm: Smoke, Hardwired, Battery Backup, Smoke Detector, Photoelectric, Hardwired Model: SM100V-AC
Grainger
21
$58.13
BRK Smoke Alarm: Smoke, Hardwired, Battery Backup, Smoke Detector, Photoelectric, Hardwired Model: SM100V-AC
Grainger
21
$38.59
BRK Hard-Wired W/Battery Back-Up Ionization Smoke Detector - AC
Bed Bath & Beyond
1K+
$38.59
BRK Hard-Wired W/Battery Back-Up Ionization Smoke Detector - AC
Bed Bath & Beyond
1K+
$42.07
BRK Hardwired Smoke Alarm 10-Year Battery Backup 1046850
DkHardware.com
32
$42.07
BRK Hardwired Smoke Alarm 10-Year Battery Backup 1046850
DkHardware.com
32
$1,067.41
BRK First Alert Hardwired Wireless Smoke Alarm W/ Voice - Pack Of 12 SA520B
DkHardware.com
3
$1,067.41
BRK First Alert Hardwired Wireless Smoke Alarm W/ Voice - Pack Of 12 SA520B
DkHardware.com
3
$39.99
BRK First Alert 10-Year Battery 2-In-1 Smoke Fire & Carbon Monoxide Alarm SMICO110
Conservation Mart
$39.99
BRK First Alert 10-Year Battery 2-In-1 Smoke Fire & Carbon Monoxide Alarm SMICO110
Conservation Mart
$83.95
10-Year Worry-Free Hardwired Smoke, Carbon Monoxide Detector, Voice Alarm 21029893
Home Depot
410
Free shipping
$83.95
10-Year Worry-Free Hardwired Smoke, Carbon Monoxide Detector, Voice Alarm 21029893
Home Depot
410
$54.99
First Alert SMCO210 Battery 2-In-1 Smoke & CO Alarm With Slim Profile Design - 5050153
Acme Tools
1K+
$54.99
First Alert SMCO210 Battery 2-In-1 Smoke & CO Alarm With Slim Profile Design - 5050153
Acme Tools
1K+
$60.81
Hardwired Interconnected Smoke And Carbon Monoxide Detector With Lithium Battery,Smoke, Co Combo Alarm With Voice Alert
Home Depot
4
Free shipping
$60.81
Hardwired Interconnected Smoke And Carbon Monoxide Detector With Lithium Battery,Smoke, Co Combo Alarm With Voice Alert
Home Depot
4
$66.45
First Alert BRK Smoke Alarm Hardwired 120V With 10 Year Sealed Lithium Battery Backup 9120LBL
Conservation Mart
8
$66.45
First Alert BRK Smoke Alarm Hardwired 120V With 10 Year Sealed Lithium Battery Backup 9120LBL
Conservation Mart
8
$289.99
First Alert BRK SMICO100-AC 2-In-1 Smoke & CO Alarm With Battery Backup 6 Pack - 5050110
Acme Tools
$289.99
First Alert BRK SMICO100-AC 2-In-1 Smoke & CO Alarm With Battery Backup 6 Pack - 5050110
Acme Tools
Replacing BRK - First Alert - Smoke Alarm
3:30
Replacing BRK - First Alert - Smoke Alarm
71.5K viewsFeb 19, 2021
YouTubeAztec Warrior
Installing new First Alert/BRK Precision Detection Hardwired Smoke alarm with existing BRK alarms
3:48
Installing new First Alert/BRK Precision Detection Hardwired Sm…
32.6K viewsJun 26, 2024
YouTubeResideo Pro
How To Replace a Hardwired Smoke & CO Detector (No Rewiring Needed!)
3:47
How To Replace a Hardwired Smoke & CO Detector (No Rewiring Need…
20K views8 months ago
YouTubeEveryday Home Repairs Help
How To Change The Battery & Trouble Shoot Fire Alarm BRK Electronics Model # 4120B
6:48
How To Change The Battery & Trouble Shoot Fire Alarm BRK Ele…
15K viewsDec 8, 2020
YouTubeWelding and stuff
Install a First Alert or BRK Hardwired Detector
2:09
Install a First Alert or BRK Hardwired Detector
10.5K viewsOct 8, 2024
YouTubeResideo Customer Support
My new BRK 4120B Smoke Alarm Overview & Test
1:34
My new BRK 4120B Smoke Alarm Overview & Test
395 views5 months ago
YouTubeBlocksguy
Learn how to replace your home smoke alarm EASY
9:50
Learn how to replace your home smoke alarm EASY
4.9K views5 months ago
YouTubeElectrical You
0:18
BRK 4120B Smoke alarm test
2K views5 months ago
YouTubeBlocksguy
1:30
Install a First Alert or BRK Battery-Powered Detector
15.7K viewsSep 30, 2024
YouTubeResideo Customer Support
6:58
Replacing a Failed Hard-Wired Smoke or Smoke/CO Detector | Fa…
187.4K views10 months ago
YouTubeEveryday Home Repairs
5:53
How to Replace Hard Wired Smoke Detectors DIY
371.6K viewsNov 25, 2022
YouTubeDIY Homestead Projects
4:09
Install a New BRK First Alert Smoke Alarm in 5 Minutes! Quick Review …
969 views7 months ago
YouTubeWanneroo
2:15
Replace Batteries on a First Alert or BRK Detector
333.2K viewsOct 21, 2024
YouTubeResideo Customer Support
1:40
Interpret Alarm Patterns and Chirps of a First Alert/BRK Detector
88K viewsSep 13, 2024
YouTubeResideo Customer Support
1:31
Clean Your First Alert/BRK Detector
13.7K viewsSep 24, 2024
YouTubeResideo Customer Support
2:19
How Do I Change the Batteries in My Smoke Detector? | Home Health
53.1K views10 months ago
YouTubeThe Design & Remodel Channel
0:51
How to replace smoke alarm (BRK SMI100-AC)
4.7K views9 months ago
YouTubePeter Ding
2:48
Learn How To Install Your Kidde Detect Alarm
292.9K viewsJul 2, 2024
YouTubeKidde Fire Safety
1:36
Stop the Beeping! How to Change a Kidde Smoke Detector Battery (FA…
72.3K views5 months ago
YouTubedigitalcamproducer
2:33
Smoke Detector 9V Battery Replacement | Stop the Chirping!
41.3K views8 months ago
YouTubeFobBattery
1:40
Testing Kidde KN-COPP-B-LPM, 0918K, I4618A (X2) and BRK SC91…
18.2K views6 months ago
YouTubeFirealarmtech1997
1:01
10-Year Battery Smoke & Carbon Monoxide Alarms | BRK
15.9K views1 year ago
YouTubeBRK Brands
4:33
How to Change Batteries in ADT Smoke Detectors
7.5K views8 months ago
YouTubeHowToWith GEO
0:31
Introducing BRK's SC5 Smart Smoke & Carbon Monoxide Alarm
612 views8 months ago
YouTubeBRK Brands
1:40
Smoke Alarm Battery Replacement - Super simple!
248.1K viewsMay 21, 2024
YouTubeExcel Electricians LTD
4:53
How to Replace Hardwired Smoke Detector – Safely Update Your Sm…
520.1K viewsMar 9, 2020
YouTubeTheRenderQ
7:09
Replace a Kidde Smoke + Carbon Monoxide Alarm in Minutes!
48.8K viewsMar 15, 2025
YouTubeFix it John
30:26
How to wire SMOKE DETECTORS. Smoke alarm wiring explained. Ma…
28.7K views11 months ago
YouTubePOUSE around the HOUSE
4:16
How to change batteries in a hardwired smoke detector
25.1K viewsMar 22, 2025
YouTubeConquerall Electrical
10:52
BRK 4120 AC powered ionization smoke alarm unboxing and review
567 viewsFeb 10, 2024
YouTubeelevators with ESH
See more videos
Static thumbnail place holder

Shop replacing brk 4120b smoke detector

Sponsored
About our ads
$13.38
BRK Electronics First Alert 4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
11
$13.38
BRK Electronics First Alert 4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
11
$54.99
$92.99
First Alert BRK SC-9120B Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup
Amazon.com
3K+
Free shipping
40% off
$54.99
$92.99
First Alert BRK SC-9120B Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup
Amazon.com
3K+
$13.38
First Alert BRK SA4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
235
$13.38
First Alert BRK SA4120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
235
$117.04
$209.99
FIRST ALERT BRK SC9120B-3 Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup, White, Pack Of 3
Amazon.com
25K+
Free shipping
44% off
$117.04
$209.99
FIRST ALERT BRK SC9120B-3 Hardwired Smoke And Carbon Monoxide (CO) Detector With Battery Backup, White, Pack Of 3
Amazon.com
25K+
$13.38
BRK Electronics First Alert 9120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
6
$13.38
BRK Electronics First Alert 9120B 120V AC/DC Hardwired With 9V Battery Backup Ionization Smoke Alarm (Upgraded To SMI100-AC)
Electric Bargain Store
6
$18.99
Sunco First Alert BRK Hardwired Ionization Smoke Alarm
Sunco
$18.99
Sunco First Alert BRK Hardwired Ionization Smoke Alarm
Sunco
$20.61
First Alert BRK Sc9120b (2 Pack) Smoke U0026 Carbon Monoxide Detector W/ Batt Backup
kreaagency
$20.61
First Alert BRK Sc9120b (2 Pack) Smoke U0026 Carbon Monoxide Detector W/ Batt Backup
kreaagency
$319.99
BRK Hard-Wired W/Battery Back-Up Photoelectric Smoke And Carbon Monoxide Detector W/Voice 6 Pk
Ace Hardware
$319.99
BRK Hard-Wired W/Battery Back-Up Photoelectric Smoke And Carbon Monoxide Detector W/Voice 6 Pk
Ace Hardware
$19.73
First Alert BRK SC9120LBL Hardwired Smoke And Carbon Monoxide (CO) Detector With 10 Year Sealed Battery Backup , White Pack Of 2
alertakey
$19.73
First Alert BRK SC9120LBL Hardwired Smoke And Carbon Monoxide (CO) Detector With 10 Year Sealed Battery Backup , White Pack Of 2
alertakey
$18.44
X-Sense Hardwired Combination Smoke And Carbon Monoxide Detector, Hardwired Interconnected Smoke And CO Detector Alarm With Replaceable Battery Backup, XP04
alertakey
$18.44
X-Sense Hardwired Combination Smoke And Carbon Monoxide Detector, Hardwired Interconnected Smoke And CO Detector Alarm With Replaceable Battery Backup, XP04
alertakey
$54.99
BRK SMICO105-AC Smoke & CO Alarm - Hardwired With Ionization Sensor With 10 Years Battery Backup
WholesaleHome
8
$54.99
BRK SMICO105-AC Smoke & CO Alarm - Hardwired With Ionization Sensor With 10 Years Battery Backup
WholesaleHome
8
$189.99
BRK SMI105-AC Hard-Wired W/Battery Back-Up Ionization Smoke Detector 6 Pk
Ace Hardware
$189.99
BRK SMI105-AC Hard-Wired W/Battery Back-Up Ionization Smoke Detector 6 Pk
Ace Hardware
$38.20
BRK Smoke Alarm: Smoke, Hardwired, Battery Backup, Smoke Detector, Ionization, Hardwired, 10 Yr Model: SMI105-AC
Grainger
32
$38.20
BRK Smoke Alarm: Smoke, Hardwired, Battery Backup, Smoke Detector, Ionization, Hardwired, 10 Yr Model: SMI105-AC
Grainger
32
$13.56
BRK 1046836 SMI100-AC Interconnectable Ion Smoke Alarm W/ Battery Backup | Supplyhouse.Com
SupplyHouse.com
21
$13.56
BRK 1046836 SMI100-AC Interconnectable Ion Smoke Alarm W/ Battery Backup | Supplyhouse.Com
SupplyHouse.com
21
$45.95
BRK 3V Battery-Operated Photoelectric Smoke Alarm - 10-Year Backup Battery - LS-SM210BRK
All Hands Fire Equipment
$45.95
BRK 3V Battery-Operated Photoelectric Smoke Alarm - 10-Year Backup Battery - LS-SM210BRK
All Hands Fire Equipment
$762.85
BRK Smoke/CO Alarm: Carbon Monoxide/Smoke, Hardwired, Battery Backup, Smoke/CO Detector, Hardwired [PK/6] Model: SMCO100V-AC
Grainger
$762.85
BRK Smoke/CO Alarm: Carbon Monoxide/Smoke, Hardwired, Battery Backup, Smoke/CO Detector, Hardwired [PK/6] Model: SMCO100V-AC
Grainger
$79.95
First Alert Brk Interconnect Hardwired Smoke Co Alarm Battery Voice
eBay
$79.95
First Alert Brk Interconnect Hardwired Smoke Co Alarm Battery Voice
eBay
$51.95
BRK Hard-Wired Photoelectric Smoke Alarm - 2X AA Backup Battery & Voice Alert - LS-SM100VACBRK
All Hands Fire Equipment
$51.95
BRK Hard-Wired Photoelectric Smoke Alarm - 2X AA Backup Battery & Voice Alert - LS-SM100VACBRK
All Hands Fire Equipment