A smart smoke detector with a CO alarm can combine fire and carbon monoxide alerts, but the right choice depends on wiring, app features, and how many alarms you need. My best overall pick is the First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm for buyers who want a smart combination alarm without hardwiring. The Kidde Smart Smoke and CO Detector with Ring is a better fit for households already using Ring, while the X-Sense SC07-W 6-Pack suits buyers prioritizing linked alarms across several rooms. The main tradeoffs are smart alerts versus simpler standalone operation, and battery-powered flexibility versus hardwired installation. Read on for how these 15 options compare and which one fits your home.
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Key Takeaways
- Smart features are not uniform: First Alert SC5 models and Kidde Ring models pair alarms with connected alerts, while several X-Sense and Kidde options focus more on local alarms, displays, or linking units.
- Your wiring changes the shortlist: Battery models such as the First Alert SC5 Battery suit homes without compatible alarm wiring; hardwired picks require installation and compatibility checks.
- Ring users have a clearer connected choice: Kidde‘s Ring-compatible smoke-and-CO models are aimed at households already using that ecosystem, while the separate Kidde Ring smoke-only model does not detect carbon monoxide.
- Multi-packs solve coverage, not necessarily app control: X-Sense SC07 3-packs, SC07-W 6-packs, Kidde 4-packs, and HEIMAN 6-packs can cover more rooms, but buyers should verify how units communicate and which alerts reach a phone.
- CO detection narrows the field: The roundup includes smoke-only products as well as combination alarms, so the Kidde Smart Smoke Detector with Ring should not be treated as a substitute for a smoke-and-CO unit.
| First Alert Hardwired Combination Smoke & Carbon Monoxide Alarm with Battery Backup |  | Best for Existing Hardwired Systems | Model: SMICO100-AC | Detection: Smoke and carbon monoxide | Power: Hardwired with 9V battery backup | VIEW ON AMAZON | See Our Full Breakdown |
| First Alert Battery Combination Smoke & Carbon Monoxide Alarm SMCO100 |  | Best for Simple Battery-Powered Setup | Model: SMCO100 | Alarm type: Combination smoke and CO alarm | Power: Battery-operated | VIEW ON AMAZON | See Our Full Breakdown |
| First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm |  | Best for App and Voice Alerts | Model: SMCO600NV | Alarm type: Smoke and carbon monoxide combination alarm | Power: Battery powered | VIEW ON AMAZON | See Our Full Breakdown |
| Kidde Smart Smoke and CO Detector with Ring, AA Battery Powered |  | Best for Ring Households | Detection: Smoke and carbon monoxide | Power: Two AA alkaline batteries, included | App connectivity: Ring app notifications | VIEW ON AMAZON | See Our Full Breakdown |
| X-Sense SC07 Smoke and Carbon Monoxide Detector Combo, 1-Pack |  | Best for Low-Maintenance Standalone Coverage | Model: SC07 | Pack size: 1-pack | Battery: Built-in sealed lithium battery | VIEW ON AMAZON | See Our Full Breakdown |
| Kidde Smart Smoke and CO Detector with Ring, Hardwired with AA Battery Backup, RGCUAR-RW |  | Best for Ring and Alexa Homes | Detection: Smoke and carbon monoxide | Power: Hardwired with AA battery backup | App alerts: Smoke, CO, and low-battery alerts through the Ring app | VIEW ON AMAZON | See Our Full Breakdown |
| Kidde Hardwired Smoke and Carbon Monoxide Detector with 10-Year Battery Backup, Voice Alerts, and LED Indicators, 4-Pack |  | Best Hardwired Multi-Room Value | Pack size: 4 detectors | Detection: Smoke and carbon monoxide | Power: 120V AC hardwired | VIEW ON AMAZON | See Our Full Breakdown |
| X-Sense SC07 Smoke and Carbon Monoxide Detector Combo, 3-Pack |  | Best for Standalone CO Readouts | Model: SC07 | Quantity: 3 alarms | Sensors: Photoelectric smoke sensor and electrochemical CO sensor | VIEW ON AMAZON | See Our Full Breakdown |
| X-Sense Smoke and Carbon Monoxide Detector SC01, 10-Year Battery, LCD Display |  | Best Simple Standalone Pick | Detection: Smoke and carbon monoxide | Sensors: Photoelectric and electrochemical | Battery: Sealed lithium battery | VIEW ON AMAZON | See Our Full Breakdown |
| X-Sense SC07-W Interconnected Smoke and Carbon Monoxide Detectors, 6-Pack |  | Best for Whole-Home Wireless Alerts | Model: SC07-W | Quantity: 6 alarms | Power: Battery-powered with sealed lithium metal batteries | VIEW ON AMAZON | See Our Full Breakdown |
| First Alert SC5 Hardwired Smart Smoke and Carbon Monoxide Alarm |  | Best for Whole-Home App Alerts | Alarm type: Smoke and carbon monoxide combination alarm | Power: Hardwired, corded electric | Battery backup: 3V lithium battery pack | VIEW ON AMAZON | See Our Full Breakdown |
| Kidde Hardwired Smart Smoke and Carbon Monoxide Detector with App Alerts and Battery Backup |  | Best for Low-Battery App Notifications | Model: 30CUAR-W | Power: 120V AC hardwired | Backup batteries: 2 AA batteries, included | VIEW ON AMAZON | See Our Full Breakdown |
| First Alert Hardwire Combination Smoke & Carbon Monoxide Alarm |  | Best for Reducing Cooking Nuisance Alarms | Alarm type: Combination smoke and carbon monoxide alarm | Power: Hardwired with battery backup | Sensing technology: First Alert Precision Detection | VIEW ON AMAZON | See Our Full Breakdown |
| HEIMAN Smoke and Carbon Monoxide Detector Combo, 10-Year Sealed Battery, 6-Pack |  | Best Multi-Room Battery-Powered Set | Pack size: 6 alarms | Detection: Smoke and carbon monoxide | Smoke sensor: Dual-beam photoelectric | VIEW ON AMAZON | See Our Full Breakdown |
| Kidde Smart Smoke Detector with Ring, AA Battery, RGSDR-RW |  | Best for Ring-Connected Smoke Alerts | Model: RGSDR-RW | Power: 2 AA alkaline batteries, included | Connectivity: Ring app notifications and wire-free interconnection with compatible Kidde alarms | VIEW ON AMAZON | See Our Full Breakdown |
| smart smoke detector with co alarm | Power | Model | Detection |
|---|---|---|---|
| First Alert Hardwired Combinat | Hardwired with 9V battery backup | SMICO100-AC | Smoke and carbon monoxide |
| First Alert Battery Combinatio | Battery-operated | SMCO100 | — |
| First Alert SC5 Battery Smart | Battery powered | SMCO600NV | — |
| Kidde Smart Smoke and CO Detec | Two AA alkaline batteries, included | — | Smoke and carbon monoxide |
| X-Sense SC07 Smoke and Carbon | — | SC07 | — |
| Kidde Smart Smoke and CO Detec | Hardwired with AA battery backup | RGCUAR-RW | Smoke and carbon monoxide |
| Kidde Hardwired Smoke and Carb | 120V AC hardwired | — | Smoke and carbon monoxide |
| X-Sense SC07 Smoke and Carbon | Sealed lithium battery | SC07 | — |
| X-Sense Smoke and Carbon Monox | — | — | Smoke and carbon monoxide |
| X-Sense SC07-W Interconnected | Battery-powered with sealed lithium metal batteries | SC07-W | — |
| First Alert SC5 Hardwired Smar | Hardwired, corded electric | — | — |
| Kidde Hardwired Smart Smoke an | 120V AC hardwired | 30CUAR-W | Smoke and carbon monoxide |
| First Alert Hardwire Combinati | Hardwired with battery backup | — | — |
| HEIMAN Smoke and Carbon Monoxi | — | — | Smoke and carbon monoxide |
| Kidde Smart Smoke Detector wit | 2 AA alkaline batteries, included | RGSDR-RW | Smoke |
More Details on Our Top Picks
First Alert Hardwired Combination Smoke & Carbon Monoxide Alarm with Battery Backup
For a home already wired for alarms, this First Alert combines smoke and CO detection with a 9V backup battery, so protection can continue during a power outage. Its interconnection with compatible First Alert and BRK alarms can help an alarm in one area alert occupants elsewhere, a practical advantage over the standalone X-Sense SC07. Advanced sensing is intended to reduce nuisance alarms, while the latching indicator helps identify which alarm sounded after an event.
The tradeoff is installation: unlike the battery-powered First Alert SMCO100, this model needs a hardwired connection and may call for professional help. Its interconnection is also limited to compatible brands, so it is a better match for an existing First Alert or BRK setup than a mixed-brand system. The supplied mounting bracket helps with fitting, but does not remove the wiring requirement.
Pros:- Combines smoke and carbon monoxide detection in one alarm.
- 9V battery backup keeps the unit powered during an outage.
- Interconnects with compatible First Alert and BRK alarms.
- Advanced sensing is designed to reduce false alarms.
Cons:- Hardwired installation may require an electrician or suitable existing wiring.
- Interconnection compatibility is limited to First Alert and BRK alarms.
- Backup depends on a replaceable 9V battery.
Best for: Homeowners replacing an existing hardwired First Alert or BRK alarm who want smoke and CO coverage with battery backup.
Not ideal for: Renters or buyers without an existing compatible hardwired alarm circuit, since installation may require electrical work and its interconnection is brand-limited.
- Model:SMICO100-AC
- Detection:Smoke and carbon monoxide
- Power:Hardwired with 9V battery backup
- Interconnectivity:Compatible First Alert and BRK alarms
- Sensing:Advanced sensing technology designed to reduce false alarms
- Indicator:Latching alarm indicator
- Mounting:Secure mounting bracket included
Our verdict“Choose this model if you have compatible hardwired First Alert or BRK alarms and want battery-backed smoke and CO coverage.”
First Alert Battery Combination Smoke & Carbon Monoxide Alarm SMCO100
The SMCO100 is the straightforward choice for buyers who want smoke and CO detection without wiring. Battery power makes placement simpler than the hardwired First Alert SMICO100-AC, and its test/silence button gives users a direct way to check the unit or quiet an alarm when appropriate. An end-of-life warning also helps signal when the alarm itself needs replacement, rather than leaving that task to memory.
It is less connected than the First Alert SC5: the SMCO100 description does not list app alerts, voice location messages, or interconnection. That keeps setup simple, but it also means this pick is not for people who want remote notifications or alarms to sound together across the house. Battery replacement remains part of ownership, and neglected maintenance can contribute to nuisance alarms. I would choose it for basic coverage, not smart-home features.
Pros:- Provides smoke and carbon monoxide detection in one battery-operated unit.
- Does not require hardwiring for installation.
- Test and silence functions are built into the alarm.
- End-of-life warning helps flag when the unit needs replacement.
Cons:- Batteries require periodic replacement.
- No app alerts, voice location alerts, or interconnection are listed.
- Poor maintenance can contribute to false alarms.
Best for: Renters and homeowners who need an easy-to-install combination alarm and prefer a simple local alert over app features.
Not ideal for: Buyers who need phone notifications, voice alerts, or linked alarms throughout the home; those features are listed for the First Alert SC5 instead.
- Model:SMCO100
- Alarm type:Combination smoke and CO alarm
- Power:Battery-operated
- Detection technology:Precision Detection
- Controls:Test/silence button
- Maintenance warning:End-of-life warning
Our verdict“Pick the SMCO100 for uncomplicated battery-powered smoke and CO coverage when connected alerts are not a priority.”
First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm
The First Alert SC5 is the most connected option in this group for buyers who want more than an audible alarm. It sends smoke and CO alerts through the First Alert app, and its voice alerts identify both the danger type and location. Compatible alarms can sound together, extending an alert beyond the room where the event starts. Compared with the battery-powered SMCO100, the SC5 adds phone notifications and location information; compared with the Ring-connected Kidde detector, it uses the First Alert app ecosystem.
Those added signals come with setup and compatibility tradeoffs: app alerts require a smartphone and app configuration, and the built-in 3V CR123A lithium batteries are a specific battery type rather than a standard AA. Its listed features make it a stronger fit for connected homes, but buyers seeking a basic alarm or a sealed 10-year battery like the X-Sense SC07 may prefer a simpler device.
Pros:- Sends smoke and CO alerts through the First Alert app.
- Voice alerts identify the danger type and location.
- Compatible alarms can sound together.
- Low-battery notifications can help prompt maintenance.
Cons:- App alerts require a compatible smartphone and app setup.
- Uses 3V CR123A lithium batteries rather than standard AA batteries.
- Connected features depend on compatible alarms and app access.
Best for: Households already using the First Alert app that want remote smoke and CO alerts, spoken danger identification, and linked compatible alarms.
Not ideal for: Buyers who do not want smartphone setup or a less common CR123A battery type, or who want a standalone alarm with a sealed 10-year battery.
- Model:SMCO600NV
- Alarm type:Smoke and carbon monoxide combination alarm
- Power:Battery powered
- Built-in batteries:3V CR123A lithium batteries
- App alerts:First Alert app
- Voice alerts:Identifies danger type and location
- Interconnectivity:Compatible alarms sound together
- Dimensions:5.75 x 1.6 x 5.75 inches
- Weight:16 ounces
Our verdict“Choose the SC5 if app notifications and spoken location details matter more to you than the simpler setup of the SMCO100.”
Kidde Smart Smoke and CO Detector with Ring, AA Battery Powered
This Kidde is the clearest fit for a home already organized around Ring: it sends smoke and CO notifications to the Ring app, including low-battery and low-level CO warnings. Its wire-free interconnection with other Kidde alarms can spread alerts through the home without hardwiring, unlike the First Alert SMICO100-AC, which needs a wired installation. Alexa notifications add another way to receive an alert, and the two included AA alkaline batteries keep installation straightforward.
The ecosystem is the main reason to choose it, but also the main limitation. Buyers using First Alert app products such as the SC5 should not assume those alarms will join Kidde’s wireless network. Optional 24/7 monitoring is sold separately, so app notifications do not mean that monitoring is included. The sensing design aims to reduce cooking-related nuisance alarms, though this remains a battery-powered system with periodic battery replacement.
Pros:- Detects both smoke and carbon monoxide.
- Ring app can provide smoke, CO, low-battery, and low-level CO alerts.
- Wire-free interconnection works with compatible Kidde alarms.
- Uses included AA batteries and supports Alexa notifications.
Cons:- Optional 24/7 monitoring is sold separately.
- Requires periodic replacement of two AA alkaline batteries.
- Wireless interconnection is for compatible Kidde alarms, not a universal mixed-brand system.
Best for: Ring and Alexa households that want app notifications, low-level CO warnings, and wireless linking with compatible Kidde alarms.
Not ideal for: Buyers invested in First Alert alarms or seeking included 24/7 monitoring, since this model uses the Ring/Kidde ecosystem and monitoring is separate.
- Detection:Smoke and carbon monoxide
- Power:Two AA alkaline batteries, included
- App connectivity:Ring app notifications
- Interconnectivity:Wire-free interconnection with compatible Kidde alarms
- Alexa compatibility:Notifications from Alexa-enabled devices
- Sensing:Designed to reduce cooking-related nuisance alarms
- Standards:UL 217 and FCC requirements
- Monitoring:Optional 24/7 monitoring sold separately
Our verdict“Choose this Kidde if your household uses Ring or Alexa and you want wireless alerts without hardwiring.”
X-Sense SC07 Smoke and Carbon Monoxide Detector Combo, 1-Pack
The X-Sense SC07 suits buyers who want smoke and CO coverage without wiring, app setup, or routine battery swaps. Its sealed 10-year lithium battery removes the recurring replacement task that comes with the First Alert SMCO100 and the AA-powered Kidde Ring detector. A photoelectric smoke sensor is intended to respond to smoldering fires and reduce cooking-related false alarms, while an electrochemical sensor handles CO detection. The included mounting hardware supports wall or ceiling installation.
The tradeoff is isolation: this is a standalone alarm with no interconnection, Wi-Fi, or base station support. It cannot match the First Alert SC5’s app alerts or the Kidde’s linked-alarm notifications. UL 217 and UL 2034 certification provide listed standards information, but do not add connectivity. This is a sensible pick for one room or a buyer prioritizing minimal battery maintenance, not for someone building a coordinated smart alarm system.
Pros:- Sealed 10-year lithium battery avoids routine battery replacements.
- Photoelectric smoke sensor is designed for smoldering-fire detection and fewer cooking-related alarms.
- Electrochemical sensor detects carbon monoxide.
- Includes mounting hardware and requires no rewiring.
Cons:- No wireless interconnection with other alarms.
- No Wi-Fi, app alerts, or base station support.
- A single standalone unit cannot provide coordinated alerts across a home.
Best for: Buyers who want a single, easy-to-mount smoke and CO alarm with a sealed battery and no ongoing battery replacement.
Not ideal for: Households needing alarms to link across rooms or send smartphone alerts; the First Alert SC5 and Ring-connected Kidde offer connected features this unit lacks.
- Model:SC07
- Pack size:1-pack
- Battery:Built-in sealed lithium battery
- Battery life:10 years
- Smoke sensor:Photoelectric
- CO sensor:Electrochemical
- Interconnectivity:None; standalone
- Certifications:UL 217 and UL 2034
- Installation:Wall or ceiling mount; bracket, screws, and anchor plugs included
Our verdict“Choose the SC07 for low-maintenance smoke and CO coverage in one location, but not if you need connected or linked alarms.”
Kidde Smart Smoke and CO Detector with Ring, Hardwired with AA Battery Backup, RGCUAR-RW
For buyers who want a hardwired smoke and CO alarm with app alerts, this Kidde is the most connected fit in this group. It sends smoke, carbon monoxide, and low-battery notifications through the Ring app, with Alexa-enabled device support, while its AA backup provides power protection if household electricity fails. Compared with the X-Sense SC07-W, it adds app and Alexa alerts, but the X-Sense can make multiple alarms sound together wirelessly without a Wi-Fi connection. This Kidde can connect with other hardwired alarms, though whole-home smart linking requires compatible Kidde detectors. Its sensing is designed to reduce cooking-related nuisance alarms. The tradeoff is that 24/7 professional monitoring requires an optional Ring subscription, and installation depends on existing hardwiring.
Pros:- Detects both smoke and carbon monoxide
- Sends real-time Ring app and Alexa alerts, including low-battery notifications
- AA battery backup helps maintain operation during a power outage
- Designed to reduce cooking-related nuisance alarms and can connect with other hardwired alarms
Cons:- Optional 24/7 smoke and CO monitoring requires a Ring subscription
- Whole-home smart connectivity requires adding compatible Kidde smart detectors
- Hardwired installation may require replacing an existing compatible alarm or arranging electrical work
Best for: Ring households with existing hardwired alarm wiring that want smoke, CO, and low-battery alerts on phones and Alexa devices
Not ideal for: Renters or homes without compatible hardwired wiring, and buyers who want monitoring without a subscription or wireless alarm linking
- Detection:Smoke and carbon monoxide
- Power:Hardwired with AA battery backup
- App alerts:Smoke, CO, and low-battery alerts through the Ring app
- Smart home:Alexa-enabled devices; connects with other hardwired alarms
- Monitoring:Optional 24/7 smoke and CO monitoring through a Ring subscription
- Nuisance alarm design:Sensing technology designed to reduce cooking-related alarms
- Certifications:UL 217 and FCC requirements
- Model:RGCUAR-RW
Our verdict“Choose this Kidde if your home already uses Ring and hardwired alarms and you want app alerts; pick the X-Sense SC07-W instead if wireless unit-to-unit sound is your priority.”
Kidde Hardwired Smoke and Carbon Monoxide Detector with 10-Year Battery Backup, Voice Alerts, and LED Indicators, 4-Pack
This four-pack suits homeowners who want to replace several wired alarms at once without adding app setup or a subscription. Each unit detects smoke and carbon monoxide, and voice alerts identify which hazard triggered the alarm—more informative than the basic standalone X-Sense SC01, which has an 85 dB alarm but no stated voice alerts. A 10-year battery backup cuts down on backup-battery changes, while compatible interconnection can make connected alarms sound together. That network depends on the other alarm models and their wiring requirements, so compatibility needs checking before purchase. Unlike the Ring-connected Kidde RGCUAR-RW, this pack does not list app or Alexa notifications. It also requires 120V AC wiring, making it a better fit for planned replacements than for renters or homes without existing alarm circuits.
Pros:- Four alarms support multi-room replacement in one purchase
- Detects both smoke and carbon monoxide
- Voice alerts identify whether smoke or CO triggered the alarm
- 10-year battery backup reduces the need for routine backup-battery changes
Cons:- Requires 120V AC wiring and ceiling installation
- Interconnection compatibility and installation requirements vary by alarm model
- Does not list app alerts or Alexa integration, unlike the Kidde Ring RGCUAR-RW
Best for: Homeowners replacing several 120V hardwired alarms who want voice identification of smoke versus CO and long-term backup power
Not ideal for: Renters, homes without compatible hardwired alarm circuits, or buyers seeking app notifications and smart-home integration
- Pack size:4 detectors
- Detection:Smoke and carbon monoxide
- Power:120V AC hardwired
- Battery backup:10 years
- Alerts:Voice alerts and LED warning indicators
- Interconnection:Compatible alarms can sound together; requirements vary by model
- Standards:UL 217 9th Edition, UL 2034 4th Edition, and FCC
Our verdict“Pick this four-pack for a wired, multi-room replacement with voice warnings, but choose the Kidde RGCUAR-RW if phone and Alexa alerts matter more than covering several locations.”
X-Sense SC07 Smoke and Carbon Monoxide Detector Combo, 3-Pack
The SC07 is a practical choice when the goal is smoke and CO coverage without rewiring, with a useful advantage over the simpler X-Sense SC01: its LCD displays real-time carbon monoxide levels and battery status. Each alarm uses photoelectric smoke and electrochemical CO sensors, and a sealed lithium battery is designed to last 10 years. The three-pack can cover multiple rooms, but the alarms work independently: unlike the X-Sense SC07-W six-pack, this version does not wirelessly relay an alert from one unit to the others. It also has no Wi-Fi or base-station support, so it is not a smart-phone notification system despite the roundup’s smart-alarm focus. For buyers who value visible CO readings and simple wall or ceiling mounting over connected alerts, that simpler setup may be the right tradeoff.
Pros:- Photoelectric smoke and electrochemical CO sensors cover both hazards
- LCD shows real-time CO levels and battery status
- Sealed lithium battery is designed for up to 10 years of power
- Three alarms mount on a wall or ceiling without rewiring
Cons:- No wireless interconnection, so one alarm does not relay its warning to the others
- No Wi-Fi, app notifications, or base-station compatibility
- Standalone design offers less whole-home alert coordination than the X-Sense SC07-W
Best for: Households wanting several easy-to-install alarms with a visible CO-level readout but no need for wireless linking or app alerts
Not ideal for: Buyers who need alarms to sound throughout the home when one unit detects danger, or who want Wi-Fi notifications
- Model:SC07
- Quantity:3 alarms
- Sensors:Photoelectric smoke sensor and electrochemical CO sensor
- Power:Sealed lithium battery
- Battery life:10 years
- Display:LCD with real-time CO levels and battery status
- Installation:Standalone wall or ceiling mount; not hardwired
- Connectivity:No wireless interconnection or Wi-Fi
- Certifications:UL 217 and UL 2034
Our verdict“Choose the SC07 three-pack if you want visible CO readings and simple battery-powered installation; choose the SC07-W if linked alarms matter more than keeping the setup standalone.”
X-Sense Smoke and Carbon Monoxide Detector SC01, 10-Year Battery, LCD Display
The SC01 is the stripped-back option for buyers who want a single alarm for smoke and carbon monoxide without wiring or smart-home setup. Its sealed 10-year battery avoids routine battery replacement, while the LCD adds information beyond the basic audible warning. It uses photoelectric and electrochemical sensors and produces an 85 dB alarm. Compared with the three-pack X-Sense SC07, the SC01 is positioned as a simpler standalone choice; the SC07’s stated advantage is a display that shows real-time CO levels and battery status, while neither model offers Wi-Fi or interconnection. That makes this a poor fit for households that want alerts relayed across rooms or sent to a phone. It can fill a straightforward coverage need, but it is not a smart detector in the connected-notification sense.
Pros:- Combines smoke and CO detection in one unit
- Sealed battery is designed to last 10 years
- Installs without alarm wiring
- 85 dB alarm provides an audible local warning
Cons:- No Wi-Fi or smart-phone alerts
- No interconnection with other alarms
- Compared with the X-Sense SC07, its listed features do not include a real-time CO-level display
Best for: Buyers adding one easy-to-install smoke and CO alarm in a home where standalone audible alerts are sufficient
Not ideal for: Families seeking linked whole-home alarms, phone alerts, or a displayed real-time CO reading
- Detection:Smoke and carbon monoxide
- Sensors:Photoelectric and electrochemical
- Battery:Sealed lithium battery
- Battery life:10 years
- Alarm sound:85 dB
- Interconnection:Not supported
- Certification:UL 217 and UL 2034
Our verdict“Choose the SC01 for straightforward standalone smoke and CO coverage, but step up to a connected model if you need remote alerts or alarms that sound together.”
X-Sense SC07-W Interconnected Smoke and Carbon Monoxide Detectors, 6-Pack
When alerting every room matters more than getting a phone notification, this six-pack has a clear advantage: wireless interconnection makes all units sound when one detects smoke or CO. That separates it from the standalone X-Sense SC07 three-pack, whose LCD shows CO levels but whose alarms do not link, and from the app-connected Kidde RGCUAR-RW, which offers Ring and Alexa alerts but depends on hardwired installation. The SC07-W uses sealed 10-year batteries and includes LCDs, so it avoids rewiring while providing local readings. The tradeoff is that it has no Wi-Fi; an alarm can alert linked units, but the listed features do not send notifications to a phone. Its six-alarm set best suits homes needing broad coverage rather than buyers replacing just one detector.
Pros:- Wireless interconnection makes linked alarms sound together when one detects danger
- Six alarms provide coverage across multiple rooms
- Sealed lithium batteries are designed for 10 years of operation
- LCD display and photoelectric smoke plus electrochemical CO sensors
Cons:- No Wi-Fi or phone notifications, unlike the Kidde Ring RGCUAR-RW
- Sealed batteries are not designed for routine replacement
- Six-unit set may be more coverage than buyers with a small space need
Best for: Homeowners who want several battery-powered alarms to sound together across rooms without adding wiring
Not ideal for: Buyers who need app or Alexa notifications, or those who only need one or two alarms
- Model:SC07-W
- Quantity:6 alarms
- Power:Battery-powered with sealed lithium metal batteries
- Battery life:10 years
- Sensors:Photoelectric smoke sensor and electrochemical CO sensor
- Alarm volume:85 dB
- Interconnection:Wireless; interconnected units sound together
- Display:LCD
- Certifications:UL 217 and UL 2034
Our verdict“Choose the SC07-W for linked, no-rewiring coverage across a home; choose the Kidde RGCUAR-RW instead if remote app and Alexa alerts are your priority.”
First Alert SC5 Hardwired Smart Smoke and Carbon Monoxide Alarm
The SC5 is the strongest fit here for buyers who want a hardwired smoke and CO alarm with phone alerts, rather than a basic interconnected alarm. The First Alert app can report hazards remotely, while voice alerts identify the danger and its location—useful when multiple alarms are sounding. Its compatible-alarm interconnection also helps spread an alert through the home, and battery backup keeps the unit running during an outage. Compared with the First Alert Hardwire Combination Smoke & Carbon Monoxide Alarm, this model adds app connectivity; compared with the Kidde Hardwired Smart Smoke and Carbon Monoxide Detector, its listed compatibility includes Google Nest Protect. The tradeoff is a narrower installation fit: it needs a suitable hardwired connection, and app alerts mean using First Alert’s app.
Pros:- Sends smoke and carbon monoxide alerts through the First Alert app
- Voice alerts name the type and location of danger
- Compatible alarms can sound together
- Battery backup provides coverage during power outages
Cons:- Hardwired installation requires an existing compatible connection
- Remote notifications require the First Alert app
Best for: Homeowners with compatible hardwired connections who want app notifications, spoken hazard details, and interconnected alarms.
Not ideal for: Renters or buyers without compatible wiring, and anyone who prefers not to rely on a manufacturer app for remote alerts.
- Alarm type:Smoke and carbon monoxide combination alarm
- Power:Hardwired, corded electric
- Battery backup:3V lithium battery pack
- Connectivity:First Alert app alerts; compatible with Google Nest Protect
- Interconnection:Compatible alarms sound together
- Detection technology:Precision Detection Technology
- Installation:Quick Connect Plug
- Dimensions:5.75 x 1.6 x 5.75 in
Our verdict“Choose the SC5 if you have compatible wiring and want app alerts plus spoken, location-specific warnings.”
Kidde Hardwired Smart Smoke and Carbon Monoxide Detector with App Alerts and Battery Backup
This Kidde is a practical pick for households that want remote alarm and low-battery notifications from a hardwired combination detector. Its 2.4 GHz Wi-Fi connection sends phone alerts, while voice prompts identify whether smoke or carbon monoxide triggered the alarm. Compared with the First Alert SC5, the clearest listed advantage is that Kidde app notifications include low-battery alerts; the SC5 instead lists compatibility with Google Nest Protect. Two AA batteries provide outage backup, but the unit still depends on 120V hardwired power, so it is not a wire-free alternative. Wi-Fi setup also requires a 2.4 GHz network, and interconnection depends on compatible Kidde models. I’d favor it when app maintenance reminders matter more than broad ecosystem flexibility.
Pros:- Sends mobile notifications for alarms and low batteries
- Voice alerts identify the detected hazard
- Two included AA batteries provide backup during outages
- Detects both smoke and carbon monoxide
Cons:- Requires 120V AC hardwired power
- Wi-Fi setup requires a 2.4 GHz network
- Interconnection is limited to compatible alarm models
Best for: Homeowners with 120V alarm wiring and a 2.4 GHz Wi-Fi network who want phone alerts for both alarms and low batteries.
Not ideal for: Renters, homes without compatible hardwiring, or buyers whose Wi-Fi network does not support 2.4 GHz setup.
- Model:30CUAR-W
- Power:120V AC hardwired
- Backup batteries:2 AA batteries, included
- Connectivity:2.4 GHz Wi-Fi
- Detection:Smoke and carbon monoxide
- Alerts:Voice alerts and mobile notifications, including low-battery alerts
- Included components:Alarm, mounting bracket, wiring harness, 2 AA batteries, user guide, quick start guide
- Certifications:UL 217, UL 2034, FCC
Our verdict“Pick this Kidde if you have hardwiring and want app reminders about low batteries as well as smoke and CO alarms.”
First Alert Hardwire Combination Smoke & Carbon Monoxide Alarm
This First Alert prioritizes dependable hardwired smoke and CO protection over app features. Its Precision Detection technology is designed to reduce nuisance alarms from cooking while still providing early fire warning, a useful distinction for kitchens near alarm locations. Compatible units interconnect, so an alert can reach more than one room, and battery backup maintains operation during outages. Compared with the smart First Alert SC5, this model does not list app notifications or location-specific voice alerts; its appeal is the simpler feature set and Quick Connect Plug, which can simplify replacement when the existing connection is compatible. It remains a hardwired alarm, though, and older homes may need professional installation. Choose it for linked household alerts and fewer cooking disruptions, not remote monitoring.
Pros:- Precision Detection is designed to reduce cooking nuisance alarms
- Compatible alarms interconnect to alert other areas of the home
- Quick Connect Plug can simplify replacement on compatible wiring
- Battery backup supports operation during power outages
Cons:- Requires a hardwired connection and may need professional installation
- No app alerts or remote notifications are listed
- Compatible-alarm interconnection depends on the installed models
Best for: Homeowners replacing a compatible hardwired alarm who want smoke and CO detection with sensing designed to reduce cooking-related nuisance alarms.
Not ideal for: Buyers who need phone notifications, spoken hazard locations, or a battery-only installation.
- Alarm type:Combination smoke and carbon monoxide alarm
- Power:Hardwired with battery backup
- Sensing technology:First Alert Precision Detection
- Interconnectivity:Compatible alarms provide interconnected warning
- Installation:Quick Connect Plug
- Test feature:Test/silence button
Our verdict“Choose this model over the smart SC5 if nuisance-alarm reduction and straightforward hardwired replacement matter more than app alerts.”
HEIMAN Smoke and Carbon Monoxide Detector Combo, 10-Year Sealed Battery, 6-Pack
The HEIMAN six-pack is the clearest choice in this group for buyers who need to cover multiple rooms without hardwiring. Each unit combines smoke and CO detection, mounts on a wall or ceiling, and uses a sealed lithium battery designed for up to 10 years. That avoids routine battery changes, but it also means the battery is not described as user-replaceable. Its 85 dB alarm, flashing LED, and alarm memory provide local warnings and a way to check for a missed event; unlike the First Alert SC5 or either smart Kidde model, the supplied details do not list app notifications or interconnected alerts. This is a coverage-focused, stand-alone option rather than a connected smart system. Buyers should also be comfortable checking the alarm-memory light to identify a past alert.
Pros:- Six alarms support coverage across multiple rooms
- Sealed lithium battery is designed for a 10-year service life
- 85 dB alarm, flashing LED, and alarm memory provide local warning cues
- Includes hardware for wall or ceiling mounting
Cons:- The sealed battery is not described as user-replaceable
- App notifications and interconnection are not listed
- Alarm memory uses a flashing LED that may require checking to identify a missed alert
Best for: Households outfitting several rooms that want battery-powered smoke and CO alarms without hardwiring or regular battery replacement.
Not ideal for: Buyers who need phone alerts, interconnected warnings, or a user-replaceable battery.
- Pack size:6 alarms
- Detection:Smoke and carbon monoxide
- Smoke sensor:Dual-beam photoelectric
- Battery:Sealed lithium battery, designed for up to 10 years
- Alarm volume:85 dB
- Alerts and indicators:Flashing LED, alarm memory, low-battery and end-of-life warnings
- Mounting:Wall or ceiling; mounting hardware included
- Certifications:UL 217 10th Edition, ETL UL 2034 5th Edition, CSFM approved
Our verdict“Choose the HEIMAN pack for broad, wire-free room coverage, but skip it if remote or interconnected alerts are a priority.”
Kidde Smart Smoke Detector with Ring, AA Battery, RGSDR-RW
This Kidde suits buyers who want battery-powered smoke alerts in the Ring app without installing wiring. It also supports Alexa notifications and wire-free interconnection with compatible Kidde alarms, giving it a connected-home role that the stand-alone HEIMAN six-pack does not fill. Its scope is narrower than the hardwired Kidde and First Alert combination alarms: the supplied product details list smoke detection, not carbon monoxide detection. That makes it a poor fit as a single replacement for a smoke-and-CO combination alarm. Sensing is designed to reduce cooking-related nuisance alarms, while optional 24/7 smoke monitoring requires a Ring subscription. The stated faster-detection comparison comes from internal testing, so I would focus the decision on app compatibility and installation flexibility instead.
Pros:- Battery-powered installation does not require wiring
- Sends smoke and low-battery notifications through the Ring app
- Supports Alexa notifications and wire-free interconnection with compatible Kidde alarms
- Sensing is designed to reduce cooking-related nuisance alarms
Cons:- Product details list smoke detection, not carbon monoxide detection
- 24/7 smoke monitoring requires an optional Ring subscription
- The stated detection-speed comparison is based on internal testing
Best for: Ring or Alexa households seeking a battery-powered smoke detector with app notifications and compatible wire-free interconnection.
Not ideal for: Anyone seeking one device for both smoke and carbon monoxide detection, or buyers who want 24/7 monitoring without an optional subscription.
- Model:RGSDR-RW
- Power:2 AA alkaline batteries, included
- Connectivity:Ring app notifications and wire-free interconnection with compatible Kidde alarms
- Alexa compatibility:Notifications from Alexa-enabled devices
- Detection:Smoke
- Optional monitoring:24/7 smoke monitoring with a Ring subscription
- Certifications:UL 217 and FCC
Our verdict“Choose this Kidde for Ring-connected smoke alerts without wiring, but pair it with a separate CO alarm if you need both hazards covered.”
How We Picked
I ranked these alarms by how well they answer the specific need for smoke detection plus carbon monoxide protection, then separated true connected options from products that mainly offer local alerts or interconnection. I weighed power source and installation fit, the usefulness of phone notifications or voice alerts, coverage options, and practical maintenance details such as replaceable versus sealed batteries. I also treated smoke-only models as a narrower choice rather than allowing smart connectivity to make up for missing CO detection.
The order favors products with a clearer match between their stated features and common buyer needs: a smart combination alarm for general use, ecosystem-specific choices, and multi-unit coverage options follow. Battery and hardwired versions are not interchangeable; a hardwired alarm can be the better replacement when wiring is already in place, but it may be a poor fit for a home that needs a simple battery install. Product names and listed features guide this comparison; buyers should confirm app, hub, interconnection, and wiring compatibility for their specific setup.
| smart smoke detector with co alarm | Detection |
|---|---|
| First Alert Hardwired Combinat | Smoke and carbon monoxide |
| First Alert Battery Combinatio | — |
| First Alert SC5 Battery Smart | — |
| Kidde Smart Smoke and CO Detec | Smoke and carbon monoxide |
| X-Sense SC07 Smoke and Carbon | — |
| Kidde Smart Smoke and CO Detec | Smoke and carbon monoxide |
| Kidde Hardwired Smoke and Carb | Smoke and carbon monoxide |
| X-Sense SC07 Smoke and Carbon | — |
| X-Sense Smoke and Carbon Monox | Smoke and carbon monoxide |
| X-Sense SC07-W Interconnected | — |
| First Alert SC5 Hardwired Smar | — |
| Kidde Hardwired Smart Smoke an | Smoke and carbon monoxide |
| First Alert Hardwire Combinati | — |
| HEIMAN Smoke and Carbon Monoxi | Smoke and carbon monoxide |
| Kidde Smart Smoke Detector wit | Smoke |
Factors to Consider When Choosing Smart Smoke Detector With Co Alarm
Before choosing a model, I would map the decision to the home rather than starting with the app. A connected alarm only helps if it detects the hazards you need covered, fits the existing installation, and sends alerts in a way your household can act on.
Decide Whether You Need One Alarm or Whole-Home Coverage
A single combination alarm may address a specific room, but it does not automatically provide coverage throughout a home. Count existing alarms and identify areas that need smoke and CO protection before choosing a multi-pack. Packs such as the X-Sense SC07 3-pack, SC07-W 6-pack, Kidde 4-pack, and HEIMAN 6-pack may simplify buying several units, but pack size alone does not establish whether alarms interconnect. Check whether an alert at one unit sounds at the others and whether that linking is wired or wireless. A common mistake is buying enough units for the house but assuming they all send phone alerts when only local alarms are supported.
Match the Power and Mounting to Your Existing Alarms
Battery-powered alarms offer more placement flexibility, while hardwired models make more sense as replacements where compatible wiring already exists. Before buying a hardwired unit, check the existing connector, mounting plate, and model compatibility rather than relying on the word “hardwired” alone. Battery backup can keep a wired alarm operating during an outage, but it does not remove installation requirements. Sealed long-life batteries reduce routine replacement tasks, yet they also mean replacing the alarm when the battery reaches its service limit. Choose based on the work you can reasonably do now and the maintenance you want later.
Separate Phone Alerts From Local Alarm Features
“Smart” can mean app notifications, ecosystem integration, voice announcements, or linked alarms, and those features do not always arrive together. Decide whether you need remote alerts when nobody is home, clearer voice identification of smoke versus CO, or simply an audible alarm inside the house. Check whether the product needs a compatible app, hub, subscription, or other device for the specific functions you want. Ring compatibility is most useful for households already using Ring, but it should not be assumed to add every smart-home feature. Do not buy a smoke-only smart alarm when your goal is a single device that also detects carbon monoxide.
Check How Alarms Communicate Across Rooms
Interconnection matters because hearing an alarm from a distant room can be difficult, especially with closed doors or multiple floors. A multi-pack may include units intended to communicate, but confirm the exact interconnection method and whether all units in the pack are compatible with one another. Wired interconnection can be a good fit for an existing system, while wireless linking may be more convenient where adding cables is impractical. Avoid mixing models based only on the same brand name; compatibility can vary by product line and generation. If whole-home alerts are your priority, verify that the chosen setup communicates across every planned location.
Choose Maintenance Based on Your Household
Battery alarms need a plan for testing and battery or unit replacement, while hardwired alarms still need periodic checks and may rely on backup batteries. A sealed battery can reduce battery-change chores, but it does not mean the detector lasts indefinitely. LCD readouts and voice prompts can make status or hazard information easier to understand, though they add features that some buyers may not need. Think about who will maintain the alarm: a landlord, homeowner, or family member who may prefer clear audible guidance. The best fit is the one your household can keep operating and checking over time.
Pay More Only for Features You Will Use
Connected alerts, ecosystem integration, and larger linked systems can be useful when they solve a real coverage or response problem. If you mainly need a dependable local combination alarm, an app may add setup steps without changing how you respond at home. Conversely, remote notifications can matter for a household that is often away or wants alerts sent to another person. Compare the full system requirements, not just the alarm’s feature list, including compatible devices and installation needs. Let the specific gap in your current protection justify the added complexity.
Frequently Asked Questions
Does every product in this roundup detect both smoke and carbon monoxide?
No. Most listed options are combination alarms, but the Kidde Smart Smoke Detector with Ring, AA Battery, RGSDR-RW is smoke-only based on its product name and should not be counted on for CO detection. If you want one device to cover both hazards, select a model explicitly identified as a smoke and carbon monoxide alarm. Check the packaging and model documentation before replacing a combination alarm. A separate CO alarm may be needed if you choose a smoke-only model.
Can I replace my existing hardwired alarm with any hardwired model here?
Not automatically. Hardwired alarms can differ in connector, mounting plate, interconnection method, and compatibility with existing units. Check the exact model requirements and the documentation for your current alarm before purchasing. Battery backup does not make an incompatible hardwired model a direct replacement. If the wiring or compatibility is unclear, consult a qualified installer rather than assuming the alarms are interchangeable.
Are Ring-compatible Kidde alarms the best choice if I do not own Ring devices?
They may still provide alarm functions, but their connected features are most relevant to buyers who already use the Ring ecosystem. If you do not use Ring, compare the setup requirements and the alerts available without other Ring devices before choosing one. A First Alert SC5 smart combination alarm may suit someone seeking a different connected route, while a simpler X-Sense combination model may fit buyers who want local protection without prioritizing ecosystem integration. Choose based on the alerts you can actually receive and use.
Should I choose a multi-pack or buy alarms one at a time?
A multi-pack can make sense when you have several locations to cover and the included units meet the same power and feature needs. It can be a poor fit if some rooms need hardwired replacements while others need battery-powered alarms, or if you expect every unit to provide app alerts. Compare pack contents and interconnection details before treating several alarms as one coordinated system. Buying individually can make placement and model matching easier, but it may leave you with a less consistent setup. Start with a room-by-room coverage plan.
Is a long-life or sealed battery model maintenance-free?
No. A long-life or sealed battery can reduce routine battery changes, but the alarm still needs regular checks and replacement according to its service-life instructions. Sealed batteries also mean you generally replace the unit rather than install a fresh battery when the power source reaches its limit. Confirm how the alarm signals low battery or end of service life, especially if nobody checks it often. Choose this design to reduce battery chores, not to avoid maintenance altogether.
Conclusion
For most buyers seeking a connected combination alarm, I would start with the First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarm as the best overall fit, with the First Alert SC5 Hardwired Smart Alarm a stronger match when compatible wiring is already available. My best value direction is a straightforward X-Sense SC07 combination alarm when app connectivity is not the main goal; the 3-pack is more practical for covering several rooms. For a premium, ecosystem-led setup, choose a Kidde Ring smoke-and-CO model if Ring integration fits your household, and consider the hardwired version when replacing compatible wired alarms. Beginners may prefer a battery-powered combination alarm with a clear, uncomplicated setup, while buyers prioritizing broad coverage should compare the X-Sense SC07-W 6-pack and other multi-packs by interconnection and alert behavior—not pack size alone. Skip the Kidde Ring smoke-only model if you need CO detection in the same device.
