THIS detector continues to low battery chirp inspite of a battery change. Should I replace the whole unit?

Try calling BRK at 800-323-9005. I had a problem with mine and they just sent me out a new unit. If your's is still under warranty, they may do the same for you.

I read in comments that this unit is an exact replacement and upgrade for the BRK 4120B (smoke only) unit. My question is, when should smoke/CO alarms be replaced? 5 years? 10 years? 30 years? Does the manufacturer have a recommended replacement time?

New CO detectors usually have an end of life warning (they start chirping every minute or so). The "life" is usually the warranty period (7 years for this unit). The "life" of the detectors is limited because they use trace amounts of radioactive material that decays over time and so its ability to detect CO or smoke decreases over time. Old detectors often do not have an end-of-life signal, but nevertheless they are probably not as effective as they should after 7 to 10 years.

does the package include adapter plugs

Yes. Each unit includes the 6-to-7 inch 3-wire jumper cable (most systems only use two of the wires: the + & -). The rectangular connector plugs into the sensor, and the wires are typically connected to the house wiring via an electrical wire nut (not included, unless you are replacing an existing unit in your house already wired with one - if so then reuse the nut if in good condition). The 9-volt batteries are for backup - I recommend the Energizer Lithium units that will last 5-to-10 years. Be safe with the electrical wiring and good luck - get professional help if you need it!

Can you replace one First Alert Smoke alarm with the smoke/Carbon Monoxide alarm on a system of 6 other just smoke alarms? I only need one with carbon monoxide detecting alarm, that would be the alarm closest to my garage, I don't have any gas running products in my home. Would it still work with the other series of al…

Yes you can. I have a system with 9 units. I have replaced several of the smoke alarms with smoke/carbon combination units. You can even reuse the connectors to save having to shut off the breaker and rewire.

Brand	First Alert
Style	10-year limited warranty
Power Source	Battery Powered
Color	WHITE
Product Dimensions	2.25"D x 5.59"W x 5.69"H
Item Weight	0.65 Pounds
Alarm	Audible
Operating Humidity	10-95% RH
Sensor Type	Ionization
Global Trade Identification Number	00029054513069, 00029054856425
Material	Plastic
Number of Items	1
Manufacturer	BRK Brands
UPC	000665889651 696720180278 099461840898 029054856425 029054513069
Part Number	SC9120B
Item Weight	10.4 ounces
Item model number	SC9120B
Batteries	1 9V batteries required.
Is Discontinued By Manufacturer	No
Size	1 Pack
Shape	Round
Voltage	120 Volts
Item Package Quantity	1
Usage	Indoor use only
Included Components	First Alert SC9120B Combination Wire-In Single/Multiple Station Smoke and CO Detector 120V AC
Batteries Included?	No
Batteries Required?	No
Battery Cell Type	Alkaline
Description Pile	9V
Warranty Description	10 Years Limited

First AlertBRK SC-9120B Hardwired Smoke and Carbon Monoxide Alarm with Battery Backup

Details

Description

Specifications

Have a Question? See What Others Asked

Common Questions