First Alert SC9120LBL Hardwired Smoke and CO Alarm
- 120V AC hardwired with 10 year lithium backup
- Ionization smoke and electrochemical CO sensors
- Locked battery drawer
- Latching alarm indicator
- Quick-connect harness
- 10-year limited warranty
Updated 5 days ago · Based on the Amazon listing and published specifications, not hands-on testing.
A hardwired smoke and CO combination alarm with a sealed ten year backup battery and latching indicator. It uses an ionization smoke sensor, so households wanting photoelectric sensing should choose another model.
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ASIN: B01ATYNULCModel: SC9120LBLCategory: Combination Smoke & Carbon Monoxide Detectors
Overview
First Alert pairs an ionization smoke sensor with an electrochemical CO sensor in this hardwired alarm, backed by a sealed lithium battery in a locked drawer. A latching light shows which interconnected unit first sounded.
No battery changes for the alarm's life and two hazards in one device cut upkeep. Quick-connect wiring speeds replacements. The smoke sensor is ionization only.
Who it's for
Homeowners replacing older hardwired alarms suit the quick-connect harness. Rentals needing tamper resistance benefit from the locked drawer.
Pros and cons
- Sealed long-life battery
- Smoke and CO in one unit
- Latching indicator finds the source
- Single test and silence button
- Ionization smoke sensing only
- Hardwiring requires an electrician or skill
Performance notes
The CO sensor reacts chemically to carbon monoxide, while the ionization chamber detects fast-flaming smoke particles. Intelligent sensing filters out some nuisance triggers. Battery backup covers power outages.
Specifications
| Brand | First Alert |
|---|---|
| Model | SC9120LBL |
| Dimensions & fit | |
| Item weight | 10.08 ounces |
| Power & efficiency | |
| Power Source | 120V AC/DC with 10Yr lithium battery backup |
| Compatibility & installation | |
| Installation | Quick-connect wiring harness |
| Included components | |
| Unit Count | 1 Count |
| Warranty & support | |
| Manufacturer Warranty Description | 10-year limited warranty |
| Other details | |
| Sensor Type | Electrochemical CO, Ionization smoke |
| Alarm | Latching alarm indicator |
| Controls | Single button test/silence |
| BuiltIn Media | 1 First Alert Safety Product |
| Mfr Part Number | SC9120LBL |
Frequently asked questions
Do I ever change the First Alert SC9120LBL battery?
Under normal conditions you should not have to replace the 10Yr lithium battery for the life of the alarm.
Is the First Alert SC9120LBL photoelectric?
No. It uses an ionization smoke sensor and an electrochemical CO sensor.
Can I swap it for my old hardwired alarm?
It connects to 120V AC with a quick-connect harness, and the bracket keyholes avoid removing box screws.
What does the latching indicator do?
It remembers which unit initiated an alarm.