{"product_id":"first-alert-hardwired-smoke-and-carbon-monoxide-alarm-2-pack-sc-9120b-with-battery-backup-ionization-and-electrochemical-sensor","title":"First Alert hardwired smoke and carbon monoxide alarm 2-pack — SC-9120B with battery backup, ionization and electrochemical sensor","description":"\u003cp\u003e\u003cstrong\u003eThe First Alert SC-9120B is a hardwired combination smoke and carbon monoxide alarm with electrochemical CO sensing, ionization smoke detection, and a battery backup for continuous protection.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis two-pack combines two detection technologies into a single, interconnected device designed for homes wired for hardwired alarms. The SC-9120B pairs an ionization smoke sensor—responsive to fast-flaming fires—with an electrochemical carbon monoxide sensor that minimizes false readings from household gases. Hardwiring gives you a constant power source while the included battery backup keeps the unit operational during power outages. LED indicators and a single test\/silence button make operation straightforward for both homeowners and installers.\u003c\/p\u003e\n\n\u003ch3\u003eHow does the SC-9120B detect both smoke and carbon monoxide?\u003c\/h3\u003e\n\u003cp\u003eThe unit uses two distinct sensing technologies tailored to different hazards. An ionization chamber detects small combustion particles common to fast, flaming fires, while an electrochemical cell measures CO levels to identify dangerous, odorless gas buildup. Each hazard has a dedicated LED so you can quickly tell which sensor triggered.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIonization sensor for rapid flame\/particle detection\u003c\/li\u003e\n  \u003cli\u003eElectrochemical CO sensor for stable, accurate carbon monoxide readings\u003c\/li\u003e\n  \u003cli\u003eSeparate LED status lights to distinguish smoke from CO events\u003c\/li\u003e\n  \u003cli\u003eAudible alarm patterns that differentiate hazards\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCan I connect these alarms to other units in my home?\u003c\/h3\u003e\n\u003cp\u003eYes — the SC-9120B is designed to interconnect with compatible BRK and First Alert hardwired alarms. When one interconnected unit detects a danger, all linked alarms sound, alerting occupants throughout the property. This feature is especially valuable in larger homes or multi-level layouts.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible with BRK and First Alert hardwired detectors\u003c\/li\u003e\n  \u003cli\u003eInterconnected triggering for whole-home alerts\u003c\/li\u003e\n  \u003cli\u003eWiring follows standard hardwired alarm installation practices\u003c\/li\u003e\n  \u003cli\u003eIdeal for multi-floor or large single-family residences\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the power and usability features I should know about?\u003c\/h3\u003e\n\u003cp\u003eThe SC-9120B runs on household hardwiring and includes a side-load battery compartment for backup power, ensuring operation during outages. A single test\/silence button lets you check functionality or temporarily quiet nuisance alarms without removing the unit. LEDs provide quick visual confirmation of normal, alarm, or fault states.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHardwired primary power with replaceable battery backup\u003c\/li\u003e\n  \u003cli\u003eSide-load battery compartment for easy replacement\u003c\/li\u003e\n  \u003cli\u003eSingle test\/silence button for convenient operation\u003c\/li\u003e\n  \u003cli\u003eVisual LED indicators for smoke vs. CO and unit status\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow should I maintain and install the SC-9120B for best performance?\u003c\/h3\u003e\n\u003cp\u003eInstall on ceilings or high on walls, away from drafts and kitchen steam. Test the alarms monthly using the test button, replace backup batteries at least once a year, and follow local electrical codes for hardwired connections. Regular cleaning prevents dust buildup that can degrade sensor performance.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMount on ceiling or high wall, away from HVAC and kitchens\u003c\/li\u003e\n  \u003cli\u003eMonthly function tests via the single button\u003c\/li\u003e\n  \u003cli\u003eReplace backup battery yearly or as needed\u003c\/li\u003e\n  \u003cli\u003eClean gently to avoid dust accumulation on sensors\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The First Alert SC-9120B 2-pack is aimed at homeowners, landlords, and contractors who need a reliable, code-friendly hardwired smoke and carbon monoxide solution with battery backup. It fits homes that require interconnected alarms, those who want both ionization and electrochemical sensing in one unit, and anyone seeking straightforward operation with clear visual alerts.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does the SC-9120B have battery backup?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — it is hardwired with a side-load battery backup to keep monitoring during power outages.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can these alarms interconnect with other brands?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: They interconnect with compatible BRK and First Alert hardwired detectors for whole-home alerts.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":54597509185875,"sku":"B078HW9GY4","price":157.74,"currency_code":"GBP","in_stock":true}],"url":"https:\/\/findsworth.co.uk\/products\/first-alert-hardwired-smoke-and-carbon-monoxide-alarm-2-pack-sc-9120b-with-battery-backup-ionization-and-electrochemical-sensor","provider":"Findsworth","version":"1.0","type":"link"}