8 Best Kidde Hardwired Smoke Detectors (November 2026)
The best Kidde hardwired smoke detectors include the Siterlink Hardwired Interconnected Smoke Detectors for photoelectric sensing, the Kidde Smoke Detector for most Kidde replacements, and the First Alert BRK SMI100-AC Hardwired Smoke Detector for larger interconnect systems.
On this page (5 sections)
The best Kidde hardwired smoke detector for most homes is the Kidde Smoke Detector, a 4-pack with 120V power, 9V battery backup, ionization sensing and a front-load battery door. It suits a straightforward replacement when your home already has hardwired alarm wiring.
Hardwired alarms make sense when you want alarms connected across rooms. If you are still comparing power types, start with our guide to hardwired vs battery smoke detectors.
Choose Siterlink for photoelectric sensing, or the Kidde smoke and CO model if voice alerts and carbon monoxide coverage matter more.
This roundup compares Kidde, Firex and one First Alert BRK option by sensor type, backup power, pack size, controls and interconnect limits.
For daily use, check which sensor type you want, whether backup batteries are front accessible or sealed, and how many alarms you need in one purchase. Confirm the alarm family and interconnect rules before you order, so a replacement fits your existing system.
Sensor type matters because ionization and photoelectric alarms respond to different smoke patterns. A home plan can use both types, so the best pick is rarely about brand alone.
Pack size matters just as much. A 4-pack or 6-pack can cover a whole home refresh, while a single alarm or 2-pack fits one room or a targeted CO location.
Backup power is the other daily reality. Hardwired power does the main work, but the battery backup keeps the alarm going during an outage.
Our picks at a glance
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1
Best for photoelectric sensingSiterlink Hardwired Interconnected Smoke Detectors
9.7/10 our score
See it on Amazon -
2
-
3
Best for larger interconnect systemsFirst Alert BRK SMI100-AC Hardwired Smoke Detector
9.6/10 our score
See it on Amazon
- 4
Check itKidde Smoke & Carbon Monoxide Detector
Best for voice smoke and CO alerts - 5
Check itKidde Hardwired Smoke Detector
Best for sealed battery backup - 6
Check itKidde 21007584 I4618 Firex Hardwire Ionization Smoke
Best for Firex replacement wiring - 7
Check itKidde AC Hardwired Interconnect Smoke Detector Alarm
Best for simple hush controls - 8
Check itKidde Smart Smoke & CO Detector
Best for app notifications
The best Kidde hardwired smoke detectors for each home
The Siterlink photoelectric 6-pack is the strongest overall fit for buyers who want photoelectric sensing and several alarms at once. The Kidde i12060A is the better match for a straightforward Kidde replacement project, while the remaining models focus on CO coverage, sealed backup power, Firex replacement or smart alerts.
Siterlink Hardwired Interconnected Smoke Detectors: Best for photoelectric sensing
- 120V hardwired power
- 9V battery backup
- Photoelectric sensor
- 6-pack
- Interconnects up to 12 devices
This 6-pack combines photoelectric sensing, hardwired power, battery backup and interconnection for a larger home.
Pros
- Photoelectric sensing
- 6-pack
- Test and silence button
Cons
- Interconnect limit is lower than some Kidde models
- No carbon monoxide detection
The Siterlink GS562A is the best choice here for a buyer who wants photoelectric sensing in a hardwired interconnected system. Each alarm uses 120V AC power with a 9V battery backup, so the alarms have backup power when the household supply fails.
The 6-pack fits a larger replacement project better than the single-unit Kidde options. Compare hardwired smoke detector multipacks if you need more pack-size choices.
Siterlink says up to 12 devices can be connected, with the other alarms sounding when one detects smoke.
The test button is also used to silence a non-fire alarm signal for 2 seconds. A green LED indicates operation, while a red LED indicates an alarm or warning.
The hidden indicator is designed to remain visible without being disruptive in a bedroom.
Choose this model when photoelectric sensing and a 6-pack are your main needs. Its trade-off is that it does not add carbon monoxide detection, and its stated interconnect limit is lower than several Kidde models here.
Kidde Smoke Detector: Best for most Kidde replacements
- Ionization sensing
- 120V power
- 9V battery backup
- Front-load battery door
- Pack of 4
The i12060A is a practical 4-pack for replacing hardwired Kidde alarms while keeping front-access battery changes.
Pros
- Front-load battery door
- 4-pack
- Test and hush button
Cons
- Ionization sensor only
- No carbon monoxide detection
The Kidde i12060A is the best all-around replacement for homes that want a Kidde-branded 4-pack with familiar controls. It uses ionization sensing, 120V power and a 9V battery backup.
Its front-load battery door lets you replace the backup battery without removing the alarm from its mounting bracket. The face button handles testing and hush, which helps when cooking or shower steam causes a non-threatening alarm.
Kidde describes the ionization sensor as designed to detect invisible fire particles associated with flaming fires. The package contains 4 smoke detectors, making it useful when several rooms need the same alarm model.
The 4-pack also makes matching placement easier. You can place the same alarm on each level and in bedrooms without mixing models that may have different controls or interconnect rules.
For care, the front door is the main practical benefit. Battery changes stay simple, and the test and hush button stays easy to reach from the floor in most rooms.
The trade-off is scope. This is a smoke-only alarm, so it does not add carbon monoxide detection for areas where you want both hazards covered in one unit.
Choose it when you want a simple Kidde smoke alarm without CO detection. If you prefer photoelectric sensing, compare it with the Siterlink model or our guide to the best hardwired photoelectric smoke detectors.
It also suits buyers who want a known Kidde layout. The controls, battery access and 4-pack count make it a clean fit for a multi-room refresh.
First Alert BRK SMI100-AC Hardwired Smoke Detector: Best for larger interconnect systems
- 120V AC power
- 9V battery backup
- Ionization sensor
- 6-pack
- Interconnects up to 18 compatible devices
This First Alert and BRK 6-pack suits a larger hardwired replacement project with a stated interconnect capacity of up to 18 compatible devices.
Pros
- 6-pack
- Side-load battery compartment
- Single silence and test button
Cons
- Not a Kidde-branded alarm
- Ionization sensor only
The First Alert BRK SMI100-AC is the best fit for a larger compatible interconnect system. It comes as a 6-pack and uses 120V AC power with a 9V battery backup.
Its ionization sensor is designed for fast flaming fires, and the single button handles both silence and testing. A side-load battery compartment gives you access to the battery without removing the alarm from its base.
The model's stated interconnect capacity is up to 18 compatible devices, including smoke alarms and other compatible devices. That makes it a strong option for a broader hardwired system, but compatibility with your current alarms still needs to be confirmed before installation.
Choose First Alert BRK when a 6-pack and a larger interconnect limit matter more than staying within the Kidde brand. For a Kidde versus First Alert comparison, see our guide to the best First Alert smoke detector hardwired options.
Kidde Smoke & Carbon Monoxide Detector: Best for voice smoke and CO alerts
- Smoke and carbon monoxide detection
- 120VAC power
- 2-AA battery backup
- Voice alerts
- Pack of 2
This 2-pack adds carbon monoxide detection and voice alerts to a hardwired Kidde system.
Pros
- Smoke and CO coverage
- Voice warnings
- Interconnects up to 24 Kidde devices
Cons
- Ionization smoke sensor
- 2-pack may not cover a whole home
The Kidde KN-COSM-IBA is the best option for adding smoke and carbon monoxide detection in one hardwired alarm. It uses ionization smoke sensing, 120VAC power and a 2-AA battery backup.
Voice alerts identify the type of warning with messages for fire, carbon monoxide and low battery. That can make a nighttime alert easier to understand than an alarm tone alone.
The Hush feature silences the alarm for about 9 minutes. The model supports up to 24 Kidde devices, with limits on the number of initiating devices.
The 2-pack works well for targeted placement near bedrooms or on key levels, though it may not cover a whole home by itself.
For setup, think about where CO coverage matters most. A combination alarm can reduce the number of separate units you need in those locations, while other rooms may still use smoke-only alarms.
The AA battery backup is also worth planning for. It keeps the unit working during a power failure, but you will need to replace those batteries on the usual schedule for this model.
The main trade-off is the smoke sensor type. This model uses ionization sensing for smoke, so it is not the pick if photoelectric smoke sensing is your priority.
Choose this model when CO coverage and voice alerts are more useful than a smoke-only alarm. For more CO-focused choices, read our Kidde carbon monoxide detector reviews.
Kidde Hardwired Smoke Detector: Best for sealed battery backup
- 120V wired power
- 10-year sealed lithium battery backup
- Ionization sensor
- Test and hush button
- Interconnects up to 24 Kidde devices
The i12010S pairs a hardwired ionization smoke alarm with a sealed lithium backup intended to avoid routine battery replacement.
Pros
- Sealed 10-year battery backup
- Up to 24 Kidde devices
- Test and hush button
Cons
- Single alarm
- Replacement is needed when the unit chirps at end of life
The Kidde i12010S is the best choice for buyers who want a sealed 10-year lithium battery backup. It uses 120V wired power and ionization smoke sensing, with an 85-decibel alarm.
Because the lithium battery is sealed, you do not plan routine battery changes for the backup. The unit chirps when it reaches the end of its alarm life, so replacement planning still matters.
Its test and hush button checks operation and silences nuisance alarms linked to cooking or shower steam. Kidde states that up to 24 Kidde smoke, heat or CO alarms can be interconnected, with possible connections for 6 strobe lights or relay modules.
This is a single-alarm purchase, so it suits replacing one unit or adding one location. Choose another model if you need several alarms in the same package or want photoelectric smoke sensing.
The sealed battery is the main appeal for hands-off upkeep. You avoid opening the unit for fresh batteries, but you still need to treat the end-of-life chirp as the trigger for a full replacement.
Kidde 21007584 I4618 Firex Hardwire Ionization Smoke: Best for Firex replacement wiring
- Hardwired ionization sensing
- Battery backup
- Front battery access
- Interconnects up to 24 Kidde devices
- Tamper-resistant lock
The I4618 Firex model is a single Kidde-branded replacement option with battery backup, front battery access and alarm memory.
Pros
- Front battery access
- Alarm memory
- Wiring harness included
Cons
- Single alarm
- Ionization sensor only
The Kidde 21007584 I4618 Firex is the best fit for a Firex hardwired replacement where front battery access and alarm memory matter. It is a single ionization smoke alarm with battery backup.
The front battery pull tab activates the battery without removing the alarm from its mounting bracket. Its alarm memory flashes a red LED to show which unit initiated an alarm in an interconnected system.
The model can interconnect with up to 24 Kidde devices, including smoke, CO and heat alarms, with the exact system limits set by the installation instructions. A tamper-resistant locking feature helps deter alarm removal.
Choose the I4618 when the Firex model family and front battery access fit your existing setup. It is less useful when you need a whole-home pack or want a smoke and CO combination alarm.
For daily use, alarm memory is the detail that saves time. When every alarm sounds, the flashing unit points you to the room where the alarm first started.
The pull tab also keeps setup simple. You can activate the battery after the base is mounted, which helps during a one-for-one swap.
The tamper lock is a practical extra for shared homes. It does not change detection, but it makes the alarm harder to remove casually.
The single-unit format is the clear limit. Buy it for a matching Firex replacement, not for a whole-home refresh in one box.
Kidde AC Hardwired Interconnect Smoke Detector Alarm: Best for simple hush controls
- 120V AC power
- 9V battery backup
- Ionization sensing
- One-button hush and test
- Interconnects up to 24 devices
The i12040 uses a one-button control for testing and hush, with hardwired power, battery backup and interconnection.
Pros
- One-button control
- Battery backup
- Up to 24 devices
Cons
- Single alarm
- Product data identifies ionization and photoelectric sensing
The Kidde i12040 is the best match for buyers who want one-button hush and test controls. It uses hardwired 120V power with a 9V battery backup and supports interconnection with up to 24 devices.
The one-button design keeps the main functions simple. The alarm also has a front battery pull tab, a large mounting base and a pre-stripped wiring harness with an easy-off cap.
Its product data identifies ionization and photoelectric sensing. Kidde explains that ionization and photoelectric alarms respond to different smoke patterns, so a home safety plan may use both types.
Choose this model for a single replacement alarm with simple controls and broad stated interconnect capacity. It is not the best choice if you need multiple alarms in one box or carbon monoxide detection in the same unit.
For installation, the wiring and mounting details help a one-for-one swap. The pre-stripped harness reduces tool needs, and the larger base can help cover marks left by an older alarm.
The front pull tab also keeps battery activation simple. You do not need to remove the alarm from the bracket to get the backup battery working.
The trade-off is pack size and coverage. As a single alarm, it fits a matched replacement, but it does not solve a whole-home update or add CO detection.
It suits buyers who value plain controls over extra features. If you want that clarity in every room, you would need to buy several units.
Kidde Smart Smoke & CO Detector: Best for app notifications
- Smoke and CO detection
- Hardwire and AA battery power
- Ring app notifications
- Alexa notifications
- Photoelectric and electrochemical sensors
This smart Kidde detector adds smoke and CO alerts through the Ring app, with hardwire and AA battery power.
Pros
- Ring app notifications
- Smoke and CO detection
- Alexa notifications
Cons
- Subscription is optional and sold separately for 24/7 monitoring
- Lowest score in this roundup
The Kidde RGCUAR-RW is the best choice for smart smoke and CO alerts. It uses hardwire and AA battery power, with photoelectric and electrochemical sensors for smoke and carbon monoxide.
The Ring app can send smoke, CO and low-battery notifications when you're home or away, and Alexa-enabled devices can also provide notifications. Kidde says one smart detector can provide mobile alerts for every hardwired alarm in the home when added according to the user guide.
The optional Ring subscription is sold separately for 24/7 smoke and CO monitoring. No subscription is required for the app notifications described in the product data.
Choose this model when remote alerts are worth more to you than a lower-cost basic alarm setup. It is the least suitable pick here for a simple replacement with no connected-home features.
The sensor mix is also a point in its favor. Photoelectric sensing covers smoke, while the electrochemical sensor covers carbon monoxide in the same unit.
For setup, follow the user guide for the whole-home alert feature. The value depends on correct placement and setup, not just on adding one smart detector and stopping there.
The AA battery backup keeps the unit powered during an outage. You will still need to replace those batteries, but you gain remote warnings that a basic alarm cannot send.
Choose it for connected alerts and combined smoke and CO coverage. Skip it if you want the simplest alarm with the fewest ongoing choices.
How do Kidde and Firex hardwired smoke detectors compare?
The Kidde 21007584 I4618 Firex is the clearest Firex-family option in this group, while the i12060A and i12040 are standard Kidde hardwired choices. All three use ionization sensing, but their controls and battery access differ.
The I4618 has front battery access, alarm memory and a tamper-resistant lock. The i12060A uses a front-load battery door and comes in a 4-pack.
The i12040 adds a one-button hush and test design, a 9V backup and a stated interconnect capacity of up to 24 devices.
For a Firex home, the I4618 is the natural starting point. Its alarm memory helps you find the initiating unit after a system-wide alarm, and the front pull tab keeps battery activation simple.
For a standard Kidde refresh, the i12060A is easier to plan. The 4-pack covers several rooms at once, and the front-load door makes backup battery changes straightforward.
The i12040 sits between those needs as a single unit. Its one-button control is plain to use, and its mounting base and pre-stripped harness can help with a clean swap.
Battery access is where the daily difference shows up. A front door, a pull tab and a sealed battery each change how often you handle the alarm.
Before changing an existing Firex or Kidde alarm, compare the model family, wiring harness and interconnect instructions. A similar round shape does not by itself confirm that two alarms work together.
These three are smoke-focused choices, so CO detection needs a separate combination alarm if you want both hazards in one unit. For most Firex replacements, choose the I4618.
For a multi-room Kidde refresh, choose the i12060A.
What should you check before buying a Kidde hardwired smoke detector?
Start with the existing wiring and compatible alarm family, then choose the sensor and backup type. The right pack size depends on how many alarms you are replacing at the same time.
Sensor type
Photoelectric and ionization sensors use different detection approaches. Siterlink is the photoelectric pick here, while most other smoke-only models use ionization sensing.
The i12040 data identifies both ionization and photoelectric sensing.
The best plan may include both sensor types across the home. For the difference between smoke and heat detection, read our guide to smoke detectors versus heat detectors.
Battery backup
A hardwired alarm still needs backup power for outages. The models here use 9V batteries, 2-AA batteries, AA batteries or a sealed 10-year lithium battery.
A front-load door or pull tab makes battery service easier. A sealed battery reduces routine changes, but the alarm still needs replacement when it reaches the end of its service life.
Interconnect limits
Interconnect limits vary by model. Siterlink supports up to 12 devices, while several Kidde models support up to 24 Kidde devices.
First Alert BRK states up to 18 compatible devices.
Do not mix alarms based only on brand name or appearance. Follow the exact compatibility instructions for your wiring and alarm family.
Pack size
The 4-pack Kidde i12060A and 6-pack Siterlink and First Alert BRK models suit larger replacement projects. The 2-pack Kidde smoke and CO model suits targeted CO coverage, while the single alarms fit one-for-one replacements.
Count the alarms you need before choosing a pack. A lower per-unit count can be useful when you only need one replacement, but it may leave other rooms on older alarms.
How should you install and care for a hardwired smoke detector?
Have hardwired alarms installed or replaced according to local electrical requirements and the model's instructions. Test each alarm after installation, keep the sensor openings clear and replace batteries or the full alarm when required.
Use the test button regularly as directed by the manufacturer. Keep cooking smoke and shower steam in mind when choosing placement, but never disable an alarm to prevent nuisance alerts.
When one alarm in an interconnected system sounds, check the entire home and follow your fire safety plan. For general placement and buying guidance, see our complete guide to what a smoke alarm is and our comparison of the best hardwired smoke detectors.
Start with the wiring. Turn off the correct breaker and follow the model instructions before you touch the harness or mounting hardware.
Mounting also needs care. Place alarms where the instructions allow, keep sensor openings clear of dust and paint, and make sure the unit sits secure on its bracket.
After installation, test every alarm in the system. Press the test control as directed, listen for the alarm, and confirm that interconnected units respond as expected.
For routine care, test on the schedule given by the manufacturer. A short regular check helps you catch a dead backup battery or a fault before it matters.
Keep the alarms clean without forcing air into the sensor. Light vacuuming around the outside and avoiding sprays or heavy dust near the openings can help prevent nuisance alerts.
Battery service depends on the model you chose. Front-load doors and pull tabs make changes easier, while a sealed lithium battery removes routine changes but still ends with a full alarm replacement.
When an alarm sounds, treat it as real until you know otherwise. Check the home, use alarm memory or LED signals where fitted, and follow your household fire plan.
If the alarm chirps for low battery or end of life, act on it promptly. Keep a simple record of install dates and battery changes to make replacement easier.
Which Kidde hardwired smoke detector should you choose?
Choose the Kidde Smoke Detector i12060A if you need a familiar 4-pack with ionization sensing, 120V power, 9V backup and a front-load battery door. Choose Siterlink if photoelectric sensing and a 6-pack are the priority.
Pick the Kidde smoke and CO alarm for voice warnings and combined coverage. Choose the i12010S for sealed lithium backup, the I4618 Firex for front-access Firex replacement needs, or the smart Kidde model for Ring app notifications.
For a larger system, the First Alert BRK 6-pack is the option to weigh. Its stated interconnect capacity and side-load battery access may suit a broader replacement project.
Whatever you choose, confirm the wiring and interconnect family before installation. The best Kidde hardwired smoke detector is the one that matches your existing system, sensor preference and backup-power needs.
Think about rooms as well as brands. Bedrooms, hallways and each level need coverage, and a combination alarm may make sense where CO protection matters most.
Think about upkeep too. A front door or pull tab helps with battery changes, a sealed battery reduces routine work, and app alerts add another layer of awareness.
Use sensor type as a tie breaker. Ionization and photoelectric alarms respond to different smoke patterns, and a home plan can use both rather than forcing one type everywhere.
Pack size should match the job. A single alarm fits a one-for-one swap, a 2-pack fits targeted coverage, and 4-packs or 6-packs fit a wider refresh.
Avoid mixing alarms by appearance alone. Check the model family, harness and interconnect limits so every unit sounds together.
Our top 3 picks at a glance
-
1
Best for photoelectric sensing
Siterlink Hardwired Interconnected Smoke Detectors
9.7/10 our score
See it on Amazon -
2
-
3
Best for larger interconnect systems
First Alert BRK SMI100-AC Hardwired Smoke Detector
9.6/10 our score
See it on Amazon
Frequently asked questions
What is the best Kidde hardwired smoke detector?
The best Kidde hardwired smoke detector for most replacement projects is the Kidde Smoke Detector i12060A. It uses 120V power with a 9V battery backup, has a front-load battery door and comes in a 4-pack.
Choose a photoelectric model if that sensor type fits your plan.
Are Kidde and Firex smoke detectors the same?
Kidde and Firex are represented together by the Kidde 21007584 I4618 Firex model in this roundup. It is a hardwired ionization alarm with battery backup, front battery access and interconnection with up to 24 Kidde devices.
Check your existing wiring and compatibility instructions before replacing alarms.
Can Kidde hardwired smoke detectors be interconnected?
Yes, several Kidde hardwired models here support interconnection. The smoke and CO model supports up to 24 Kidde devices, while the Siterlink model supports up to 12 devices.
Use only compatible alarms and follow the installation instructions for the exact system.
Should you choose ionization or photoelectric sensing?
Ionization sensing is designed around invisible fire particles associated with flaming fires, while photoelectric sensing is a different detection approach. The Siterlink model here uses photoelectric sensing.
Kidde recommends using both sensing types in a home to help cover different fire conditions.
Do hardwired smoke detectors still need batteries?
Most hardwired smoke detectors in this roundup include a battery backup. The backup keeps the alarm operating during a power failure.
Battery types differ, including 9V, 2-AA and a sealed 10-year lithium battery, so check the model before planning replacement.
