Best Smoke Detector (2026): 7 Picks for Every Room and Budget

Affiliate disclosure: As an Amazon Associate, Delozone earns from qualifying purchases. Some links on this page are affiliate links, so we may earn a commission at no extra cost to you. Our picks are based on published specifications, UL 217 and UL 2034 certification claims, NFPA and U.S. Fire Administration guidance and verified owner feedback. We did not run our own lab tests, and commissions never decide what we recommend.

The best smoke detector for most homes is one certified to the current UL 217 standard, powered for the full 10-year life of the alarm and interconnected so every alarm sounds at once, and our top pick is the X-Sense SC07, a photoelectric smoke and electrochemical carbon monoxide combo with a sealed 10-year lithium battery. If your home already has wiring for alarms, a hardwired model such as the First Alert SMICO100-AC or the Kidde 20SA10-V is the better choice, because NFPA data shows hardwired alarms operated in 94% of fires large enough to trigger them, against 85% for battery-only alarms.

Key takeaways

• Buy only alarms listed by a recognized testing laboratory such as UL or Intertek (ETL). The label should say the alarm is certified to UL 217 for smoke, and to UL 2034 as well if it also detects carbon monoxide.
• Since June 30, 2024, newly manufactured smoke alarms must meet the 8th edition of UL 217, which added a cooking nuisance test and faster-burning polyurethane foam fire tests, so the old ionization versus photoelectric debate matters less for new alarms.
• NFPA guidance calls for an alarm inside every bedroom, outside each sleeping area and on every level, including the basement, installed at least 10 feet from cooking appliances.
• Nearly 3 in 5 home fire deaths from 2018 to 2022 happened in homes with no smoke alarms or alarms that did not work, according to NFPA.
• Replace every smoke alarm 10 years after its manufacture date, test it monthly, and never pull the battery to stop a nuisance alarm.

Quick comparison: best smoke detectors for 2026

Model	Detects	Sensor	Power	Interconnect	Best for	Buy
X-Sense SC07	Smoke + CO	Photoelectric + electrochemical	Sealed 10-year lithium	No	Most rooms, easy upgrade	Check price
First Alert SMICO100-AC	Smoke + CO	Ionization (Precision Detection) + CO	120V hardwired, 9V backup	Wired	Replacing hardwired alarms	Check price
Kidde 20SA10-V	Smoke	Photoelectric	120V hardwired, 10-year backup	Wired (Kidde)	Hardwired homes, voice alerts	Check price
X-Sense SC07-W	Smoke + CO	Photoelectric + electrochemical	Sealed 10-year lithium	Wireless RF, up to 18	Homes without alarm wiring	Check price
Kidde Smart Smoke & CO with Ring (RGCUDR-RW)	Smoke + CO	Photoelectric + electrochemical	2 AA batteries	Wireless + Ring app	Phone alerts when away	Check price
First Alert SMI100	Smoke	Ionization (Precision Detection)	9V battery	No	Budget coverage, extra rooms	Check price
First Alert BRK 7020BSL	Smoke	Photoelectric + 177 cd strobe	Hardwired, 10-year sealed backup	Wired	Deaf or hard-of-hearing residents	Check price

What Makes a Smoke Detector Good in 2026

The UL 217 8th edition changed the rules

Every legitimate home smoke alarm sold in the U.S. is built to UL 217, the performance standard maintained by UL Standards and Engagement. According to the National Institute of Standards and Technology (NIST), the 8th edition of UL 217 took effect on June 30, 2024, and it was the first version to include a test for reducing nuisance alarms. In that test, two standardized hamburger patties are broiled 10 feet from the alarm, and the alarm passes only if it stays quiet.

The same edition added fire tests with polyurethane foam, the filling in many modern sofa cushions. NIST explains that this foam burns faster than the cotton and horsehair stuffing used in the original smoke alarm tests of the 1970s, so the old tests no longer matched real house fires. When NIST ran 45 alarms from the previous generation against the new requirements in 2016, not one of them passed, which tells you how much the bar moved.

For shoppers, the practical rule is simple. Look for “UL 217 8th Edition”, “Precision Detection” (First Alert’s name for it) or a newer edition on the box or listing, and treat alarms made before mid-2024 as the older generation. Retailers may still sell older stock, and NIST notes that the new standard applies only to newly manufactured detectors, so check the manufacture date printed on the back of the alarm.

“Modern smoke alarms are really good at detecting fires. However, they have a challenge with not detecting cooking, because cooking is almost a fire.”

Amy Mensch, mechanical engineer at NIST, on the 2024 study of new-generation smoke alarms

Photoelectric, ionization or both

Home smoke alarms use one of two sensing methods. An ionization alarm uses a tiny radioactive source to create an electric current that smoke disrupts, and it is generally faster with fast, flaming fires. A photoelectric alarm uses a light beam and a sensor that sees light scattered by smoke particles, and it is generally faster with slow, smoldering fires such as a cigarette in a couch cushion.

Both NFPA and the U.S. Fire Administration still recommend having both types in the home, or dual-sensor alarms that contain both sensors. That advice predates the new standard, and it remains a sensible belt-and-braces approach, especially if some of your alarms are older than 2024. Because no one can predict which kind of fire will start, mixing sensor types across the house costs little and covers both scenarios.

The 8th edition narrows the gap. NIST says the standards panel designed it so that every compliant alarm, whatever its sensor, must detect both smoldering and flaming fires well, and then added the cooking test so the extra sensitivity would not create more false alarms. In our picks you will see both sensor types, and every one of them is sold as meeting the current standard.

Certification marks you can trust

A certification mark means an independent laboratory checked the alarm against UL 217, and for combination units, against UL 2034 for carbon monoxide. The two marks you will see most often on U.S. alarms are UL and ETL (Intertek). Both are Nationally Recognized Testing Laboratories under OSHA, and both publish searchable directories of certified models.

Be careful with wording such as “built to UL standards” or “meets UL 217” without a listing mark. Online marketplaces carry cheap alarms from unfamiliar brands whose only evidence of performance comes from the seller, and UL Solutions has publicly warned about products carrying counterfeit UL marks. A European CE mark is not a substitute for U.S. certification either.

Every alarm in this guide comes from an established manufacturer, First Alert (Resideo and its BRK line), Kidde or X-Sense, and each listing states certification to UL 217, plus UL 2034 for the combination models. If you buy a different model, look up its model number in the UL Product iQ or Intertek directory before you mount it on the ceiling.

Power source and service life

Smoke alarms get power in 3 ways: a replaceable battery (usually 9-volt or AA), a sealed 10-year lithium battery, or your home’s 120-volt wiring with a backup battery. The U.S. Fire Administration says hardwired alarms usually have a backup battery that must be replaced once a year, unless the alarm has a sealed 10-year backup like the Kidde 20SA10-V and the First Alert BRK 7020BSL.

Power matters because missing or dead batteries are the most common reason alarms fail. The NFPA’s Smoke Alarms in US Home Fires report found that 66% of fatal injuries in homes with smoke alarms happened in properties with battery-only alarms, and that missing, disconnected or dead power sources were the most common factor when alarms failed. A sealed 10-year battery removes the temptation to borrow the battery for a remote control.

Whatever the power source, every smoke alarm has a finite life. The U.S. Fire Administration states that smoke alarms must be replaced 10 years from the manufacture date, and many modern alarms give an end-of-life chirp at that point. That is why we count the 10-year battery and a clear end-of-life warning as real features, not marketing extras.

Interconnection

Interconnected alarms talk to each other, so smoke in the basement sets off the alarm outside the bedrooms too. NFPA recommends interconnecting all alarms for the best protection, and notes that it can be done with wiring or wirelessly, as long as all alarms come from the same manufacturer and are compatible with each other.

The evidence is strong. NFPA cites a Consumer Product Safety Commission survey of household fires in which alarms that were interconnected sounded in 53% of fires and alerted occupants in 26%, while alarms that were not on all floors sounded in only 4% of fires and alerted people in just 2%. A single alarm at the far end of the house is easy to sleep through behind a closed door.

Hardwired alarms connect through a third wire in the ceiling harness, and battery alarms connect through radio frequency (RF) mesh signals. Wireless interconnect usually works only within one brand and often one product family, so choose your system before you buy the first alarm and stick with it as you add units.

The 7 Best Smoke Detectors in 2026

All 7 picks come from First Alert, Kidde or X-Sense, carry UL 217 certification according to their manufacturers, and were in stock on Amazon with a working buy box when we checked in September 2026. We ranked them on certification and standard edition, sensor type, power and service life, interconnect options and the pattern of verified owner feedback.

No single alarm is right for every ceiling. A hardwired home should replace hardwired alarms with hardwired alarms, a rental without wiring needs sealed-battery or AA units, and a household with a deaf or hard-of-hearing member needs a visual signal, so each pick is labeled with the situation it fits best.

1. X-Sense SC07: best overall smoke detector

The X-Sense SC07 combines a photoelectric smoke sensor with an electrochemical carbon monoxide sensor in one ceiling or wall unit, powered by a sealed lithium battery rated for 10 years. X-Sense states it is certified to UL 217 and UL 2034, and the interconnected SC07-W version is listed as ETL certified to both standards. The alarm sounds at 85 decibels, the level most home alarms use.

Its small LCD shows the current carbon monoxide reading in parts per million once levels rise, which is more useful than a plain status light when you are deciding whether to call the gas company. Because the battery is sealed, there are no yearly battery swaps and no low-battery chirps for a decade. When it reaches end of life, you replace the entire alarm, which is what the U.S. Fire Administration recommends anyway.

The trade-off is that the standard SC07 is a standalone unit. X-Sense notes that it does not support wireless interconnection, Wi-Fi or a base station, so if you need alarms that sound together, buy the SC07-W (pick 4) instead. For bedrooms, hallways and rooms in a home that already has a working interconnected system, the SC07 is the simplest upgrade we found.

• Detects: smoke (photoelectric) and carbon monoxide (electrochemical)
• Power: sealed 10-year lithium battery, no wiring
• Certification (maker): UL 217 and UL 2034
• Best for: bedrooms, hallways and most homes that need a simple, long-life combo alarm

Check X-Sense SC07 price on Amazon

2. First Alert SMICO100-AC: best hardwired combination alarm

If your ceilings already have hardwired alarms, the First Alert SMICO100-AC is the easiest way to replace them with current-generation smoke and CO protection. It uses First Alert’s Precision Detection sensing, which the company says complies with the new industry standards for reducing cooking nuisance alarms, and it pairs that with a carbon monoxide sensor. It runs on 120-volt household power with a 9-volt battery backup for outages.

A Quick Connect plug adapter lets it attach to many existing harnesses without rewiring, and First Alert says it interconnects with most First Alert and BRK alarms, so when one sounds, all compatible alarms sound. A latching alarm indicator shows which unit started the alarm, which helps you find the source fast in a two-story house.

The smoke sensor is ionization-based, so if your household does a lot of high-heat cooking, keep it well away from the kitchen or pair it with photoelectric alarms elsewhere, as NFPA and USFA suggest. The 9-volt backup battery needs replacing once a year. It is sold in 3-packs and 6-packs, which suits whole-house replacements.

• Detects: smoke (Precision Detection, ionization) and carbon monoxide
• Power: 120V hardwired with 9V battery backup
• Interconnect: wired, with most First Alert and BRK alarms
• Best for: replacing old hardwired smoke or combo alarms in one afternoon

Check First Alert SMICO100-AC price on Amazon

3. Kidde 20SA10-V: best hardwired smoke alarm with voice alerts

The Kidde 20SA10-V is a hardwired photoelectric smoke alarm with a built-in 10-year backup battery, so it never needs a yearly battery change. Kidde lists it as tested to UL 217 10th Edition, a newer revision than the 8th edition that became mandatory in 2024. It sounds an 85-decibel alarm, flashes a red LED and announces “Fire” by voice, which can help children and guests understand what is happening.

Kidde says its enhanced sensing helps the alarm tell the difference between real smoke and everyday cooking or shower steam. It connects to other compatible Kidde hardwired alarms, so when one detects smoke, the others sound too. It carries a 10-year limited warranty from the date of purchase, which matches the life of the alarm.

This is a smoke-only alarm, so pair it with dedicated carbon monoxide alarms near sleeping areas and on each level with fuel-burning appliances. Kidde’s harness differs from First Alert’s, so if you are replacing a different brand, plan to swap the ceiling plug too, a job that the U.S. Fire Administration says belongs to a qualified electrician for hardwired alarms.

• Detects: smoke (photoelectric)
• Power: 120V hardwired with sealed 10-year backup battery
• Standard (maker): UL 217 10th Edition
• Best for: hardwired homes that want no yearly battery changes and spoken alerts

Check Kidde 20SA10-V price on Amazon

4. X-Sense SC07-W: best interconnected alarm for homes without wiring

The X-Sense SC07-W is the wireless interconnected version of our top pick. It keeps the photoelectric smoke sensor, electrochemical CO sensor, LCD readout and sealed 10-year battery, and adds an RF link so that up to 18 X-Sense alarms can join one network. X-Sense quotes a transmission range of up to 820 feet in open space, which in practice means across floors, the basement and a detached garage in most homes.

When any alarm detects smoke or CO, every linked alarm sounds. Pressing the Test/Silence button on the alarm that started it silences the whole group temporarily. X-Sense lists it as ETL certified to UL 217 and UL 2034, and installation is a bracket and two screws, with no electrician needed.

The SC07-W does not connect to Wi-Fi or a base station, so it will not send phone notifications. For renters, older homes without a third interconnect wire and anyone who wants NFPA-style interconnection without opening ceilings, it is the most practical option we found. It is sold in 3-packs and 6-packs, which covers a typical 3-bedroom home.

• Detects: smoke (photoelectric) and carbon monoxide (electrochemical)
• Power: sealed 10-year lithium battery
• Interconnect: wireless RF, up to 18 alarms, up to 820 ft open-space range (maker)
• Best for: renters and homes without alarm wiring

Check X-Sense SC07-W price on Amazon

5. Kidde Smart Smoke & CO Detector with Ring (RGCUDR-RW): best smart smoke detector

The Kidde RGCUDR-RW is a battery-powered smoke and CO alarm that connects to the Ring app, so you get phone notifications for smoke, carbon monoxide and low batteries whether you are home or away. Kidde states that the app alerts do not require a subscription, and an optional paid Ring plan adds 24/7 professional monitoring for smoke and CO.

It uses a photoelectric smoke sensor and an electrochemical CO sensor, and Kidde says it can send low-level CO alerts to your phone before levels reach the alarm threshold. Kidde also claims over 25% faster smoke detection than a leading competitor, based on its own internal testing, and reduced cooking nuisance alarms compared with its previous generations. Wire-free interconnect links it with other Kidde smart alarms so they sound together.

It runs on 2 AA batteries, which means battery changes rather than a sealed 10-year cell, but the app warns you before they run out, so you avoid the 3 a.m. chirp. If you already use Ring cameras or a Ring alarm, this is the most natural fit. If you do not want another app or account, the SC07-W delivers interconnection without the phone features.

• Detects: smoke (photoelectric) and carbon monoxide (electrochemical)
• Power: 2 AA batteries (included)
• Smart features: Ring app alerts, low-level CO alerts, optional paid monitoring
• Best for: phone alerts when you are away and Ring households

Check Kidde Smart Smoke & CO with Ring price on Amazon

6. First Alert SMI100: best budget smoke detector

The First Alert SMI100 is a basic battery smoke alarm built to the new standard, with Precision Detection sensing that First Alert says complies with the updated requirements for reducing cooking nuisance alarms. It is one of the best-selling smoke alarms on Amazon, and it is usually sold in multipacks, which makes it an affordable way to put an alarm inside every bedroom as NFPA 72 requires.

It runs on a 9-volt battery with a front-access compartment, so battery changes do not require taking the alarm off its bracket. An end-of-life warning tells you when the alarm itself needs replacing, and a single test/silence button handles monthly testing. Installation takes a bracket and two screws.

The compromises are real: smoke only, no interconnection and a battery to replace at least once a year according to the U.S. Fire Administration. We see it as a good way to fill gaps quickly, for example adding alarms to bedrooms in an older home, while you plan a full interconnected system. Pair it with dedicated CO alarms where needed.

• Detects: smoke (Precision Detection, ionization)
• Power: 9V battery, front access
• Extras: end-of-life warning, test/silence button
• Best for: low-cost coverage in extra bedrooms and hallways

Check First Alert SMI100 price on Amazon

7. First Alert BRK 7020BSL: best smoke detector for hearing loss

The First Alert BRK 7020BSL combines a photoelectric smoke alarm with a 177-candela LED strobe in a single unit that needs only one junction box. It runs on household AC power with a sealed 10-year backup battery. When several units are installed, the strobes flash in sync, and First Alert says the strobe uses separate flash patterns to distinguish smoke from carbon monoxide when it is interconnected with compatible CO alarms.

A strobe matters because a standard 85-decibel alarm may not wake someone with hearing loss. The U.S. Fire Administration notes that alarms for people with hearing loss may use strobe lights that flash and devices that vibrate. NFPA 72 material points to visual and tactile signals, such as bed shakers, for people with moderately severe to profound hearing loss, so the 7020BSL covers the visual part of that plan.

This is a hardwired, contractor-grade alarm from First Alert’s BRK line, so it suits bedrooms of family members who are deaf or hard of hearing, and it should be installed by an electrician. It sits alongside, not instead of, the regular interconnected alarms in the rest of the home. For people who sleep deeply, add a bed shaker that is compatible with your alarm system.

• Detects: smoke (photoelectric)
• Signal: audible alarm plus 177 cd synchronized LED strobe
• Power: AC hardwired with sealed 10-year backup battery
• Best for: bedrooms of deaf or hard-of-hearing residents

Check First Alert BRK 7020BSL price on Amazon

How We Chose These Smoke Detectors

Certification and standard edition first

We started with a shortlist of more than 30 current alarms from the brands that dominate U.S. home safety, First Alert, Kidde and X-Sense, plus the models most often recommended by Consumer Reports, The Spruce, Bob Vila and Reviewed. Any model without a clear UL 217 claim from its manufacturer was dropped, and for combo units we also required UL 2034.

We then favored alarms built to the 8th edition or newer. That is why the First Alert picks carry the Precision Detection label and why the Kidde 20SA10-V, listed to the 10th edition, made the list over older Kidde hardwired models that are still widely sold. Older-generation alarms still work, but a new purchase should last 10 years, so it makes sense to buy the current standard.

Unfamiliar marketplace brands with no verifiable listing were excluded even when their specifications looked attractive. A smoke alarm is a life-safety device, and a certification you can look up is the minimum bar.

Power, service life and interconnect

Next we scored how each alarm is powered and how long it runs without attention. Sealed 10-year batteries and hardwired power with a 10-year backup scored highest, because NFPA’s data links most alarm failures to missing or dead power sources. Replaceable 9-volt and AA models stayed in only where they bring something else, such as low cost or smart features.

Interconnect options were the third filter. We looked for wired interconnect on hardwired models and RF interconnect on battery models, and we noted which brands and product families can link together, because mixing brands usually breaks the chain.

Finally, we checked that each alarm fits a real situation: whole-house hardwired replacement, rentals, smart homes, budget gap-filling or hearing loss. That is why the list has 7 different winners instead of 7 versions of the same alarm.

Owner feedback and availability

We read verified owner reviews for recurring patterns rather than star averages: false alarms from cooking or steam, early failures, confusing chirps, pairing problems and customer service. Models with a consistent pattern of serious complaints were dropped or moved to our caveats, which is what happened to the First Alert SC5, discussed below.

Every pick was checked on Amazon in September 2026 for a working buy box, meaning it was actually available to buy. Prices change often, so we link to current prices instead of printing numbers that go stale.

We did not run our own lab or smoke tests. Our choices rely on manufacturer specifications, certification claims, NFPA, NIST and U.S. Fire Administration guidance, published testing from independent reviewers and verified owner feedback, and we update the guide when models or standards change.

Where to Install Smoke Detectors

Bedrooms, sleeping areas and every level

NFPA 72, the National Fire Alarm and Signaling Code, has long required smoke alarms inside every sleeping room, outside each sleeping area and on every level of the home, including the basement. According to NFPA’s installation guidance, this applies even in existing homes, and larger homes need additional alarms. Many older homes were built to earlier rules and have alarms only in hallways.

On levels without bedrooms, NFPA recommends an alarm in the living room, den or family room, or near the stairway to the upper level, or in both. In the basement, the alarm should go on the ceiling at the bottom of the stairs leading up, because smoke rises up the stairwell toward the sleeping floors.

The U.S. Fire Administration adds that a closed bedroom door can slow the spread of smoke, heat and fire. That is exactly why the alarm inside the bedroom matters: behind a closed door, you may not hear an alarm in the hallway until smoke is already on the other side.

Ceiling, wall and pitched ceilings

Smoke rises, so alarms go on the ceiling or high on a wall. NFPA says wall-mounted alarms should be installed no more than 12 inches from the ceiling, measured to the top of the alarm. On a pitched ceiling, install the alarm within 3 feet of the peak but not in the apex itself, at least 4 inches down from the peak, where trapped hot air can keep smoke away.

Avoid spots near windows, doors and heating or cooling ducts, where drafts can blow smoke away from the sensor or push dust into it. NFPA also warns never to paint an alarm or cover it with stickers, because paint and decorations can block the openings.

Always follow the manufacturer’s instructions as well. Each alarm’s manual lists its own distance rules, and combination smoke and CO units sometimes have placement limits that differ from smoke-only alarms, such as distance from fuel-burning appliances.

Kitchens, bathrooms and nuisance alarms

NFPA says smoke alarms should be installed at least 10 feet from a cooking appliance to minimize false alarms. Its guidance on alarm types adds that where an alarm must sit between 10 and 20 feet from a cooking appliance, a photoelectric alarm or one with a hush button is the better choice. NIST’s own tip is to place alarms at least 6 feet and ideally 20 feet from the cooking area and to keep the kitchen well ventilated.

Bathrooms create the same problem with steam. Keep alarms outside the bathroom door where possible, and run the exhaust fan during and after showers. If steam still sets off a nearby alarm, the U.S. Fire Administration suggests moving the entire alarm several feet away from the bathroom rather than disabling it.

False alarms are a safety issue, not only an annoyance. NIST researchers note that people who repeatedly get nuisance alarms tend to disable their devices, and a disabled alarm cannot warn you of a real fire. Placement is the cheapest fix, and a current-standard alarm is the second.

Garages, attics and when to use a heat alarm

Garages, attics, unheated porches and furnace rooms can be too hot, cold, dusty or humid for a smoke alarm to work reliably. Manufacturers publish temperature and humidity limits for each alarm, for example Kidde lists an upper temperature rating of 100°F and 10 to 95% non-condensing humidity for the 20SA10-V, and outside those limits an alarm may false-alarm or fail. That is where a heat alarm comes in.

A heat alarm sounds when the temperature reaches a fixed point, commonly 135°F, or rises very quickly. It will not warn you of a smoldering fire, so it never replaces smoke alarms in living areas, but it adds early warning from places where a smoke alarm would be unreliable. The U.S. Fire Administration lists heat alarms among its home fire safety resources for this reason.

If your hardwired alarms are Kidde, a compatible Kidde heat alarm can join the same interconnect, so a garage fire sets off the alarms inside the house. First Alert’s BRK line offers a similar hardwired heat alarm for First Alert systems.

How many smoke detectors do you need

Count one alarm for every bedroom, one for each sleeping area’s hallway, one for every level without bedrooms and one for the basement. Then add alarms for large open areas, since NFPA notes that larger homes need more than the minimum. Many households find they need 2 to 3 more alarms than they currently have.

The table below shows a typical count for a two-story, 3-bedroom house with a basement. Use it as a starting point, and check your local building code, which can require specific alarm types, hardwiring in new construction or combination CO alarms.

Location	Alarms	Suggested type
Bedrooms (3)	3	Smoke or smoke + CO, interconnected
Upstairs hallway outside bedrooms	1	Smoke + CO combo
Main floor living room or stair	1	Photoelectric smoke, 10+ ft from kitchen
Basement ceiling at bottom of stairs	1	Smoke + CO combo if furnace or water heater is there
Attached garage (optional)	1	Heat alarm, interconnected
Total	6 to 7	All from one compatible family

If your household relies on the same system for carbon monoxide, read our guide to the best carbon monoxide detectors for CO placement rules, which differ from smoke placement, and the CO levels that should prompt you to act.

Smoke Detectors for Specific Situations

Renters and homes without wiring

If you rent or your home has no alarm wiring, sealed 10-year battery alarms with wireless interconnect give you nearly the same protection as a hardwired system. The X-Sense SC07-W links up to 18 alarms, and the Kidde Ring model adds phone alerts. Both install with screws, so they come down cleanly when you move.

Landlords are usually responsible for providing working alarms under state and local law, so tell your landlord if alarms are missing or expired. Adding your own interconnected units on top of the landlord’s alarms is still a reasonable step, especially in bedrooms that lack one.

Some fire departments install battery alarms for free, according to the U.S. Fire Administration. Call your local department’s non-emergency number and ask, especially if cost is the only thing standing between your household and working alarms.

Replacing old hardwired alarms

Replacing hardwired alarms is simplest when you stay with the same brand, because the ceiling plug and interconnect signal match. First Alert and BRK alarms generally work together, and the SMICO100-AC includes a Quick Connect adapter for many existing First Alert and BRK harnesses. Kidde alarms use Kidde harnesses, so check Kidde’s compatibility notes in the manual before mixing generations.

If you switch brands, you usually need to replace the ceiling plug on every alarm in the chain, because brands use different connectors and interconnect signals. Mixing brands on one interconnect line can mean one alarm sounds while the others stay silent, which defeats the purpose.

The U.S. Fire Administration says only qualified electricians should install hardwired smoke alarms. Swapping a like-for-like plug-in unit is simple, but new circuits, new boxes and changing harnesses are electrician work, and some jurisdictions require a permit.

Deaf and hard-of-hearing residents

A standard alarm relies on sound, and many people who are deaf or hard of hearing will not wake to it. NFPA 72 material describes a 520 Hz low-frequency alarm signal for sleeping rooms, which is easier to hear for people with mild to severe hearing loss than the high-pitched tone of a standard alarm. For moderately severe to profound hearing loss, the approach shifts to visual and tactile signals: strobes and bed or pillow shakers.

The First Alert BRK 7020BSL provides the strobe, with a 177-candela light that flashes in sync across multiple units. Bed shakers and low-frequency sounders are usually sold as accessories that connect to a specific alarm system, so confirm compatibility before buying.

Plan the system around the person. Put the visual and tactile signals in their bedroom, keep standard interconnected alarms everywhere else, and make sure everyone in the household knows the escape plan.

Smart homes and Google Home users

Google stopped making the Nest Protect in March 2025 and began selling through remaining stock. Existing units continue to work until they expire, and Google’s Nest Protect support page says Google partnered with First Alert to offer a compatible replacement for the second-generation Nest Protect in the Google Home app: the First Alert SC5 Smart Smoke & Carbon Monoxide Alarm.

The SC5 (model SMCO600NV and the hardwired SMCO600NV-AC) offers app alerts, voice warnings that name the type and location of danger, and compatibility with existing Nest Protect units in the Google Home app. However, verified owner feedback on Amazon has been notably mixed, with repeated complaints about setup and app connection, so we did not rank it. If you must replace a Nest Protect inside an existing Google Home setup, it is the official path, but read recent reviews before buying.

Outside the Google ecosystem, the Kidde smart alarms with Ring are the most straightforward choice today. Whichever you choose, remember that the app is a bonus: the alarm must still work as a loud, local, interconnected alarm when the Wi-Fi is down.

Check First Alert SC5 (hardwired) on Amazon

Combination smoke and CO alarms

A combination alarm saves ceiling space and is required in some jurisdictions for new or renovated homes. The CDC estimates that more than 400 Americans die from accidental carbon monoxide poisoning every year, and any home with a fuel-burning appliance, fireplace or attached garage needs CO protection. Combination units must be certified to both UL 217 and UL 2034.

The catch is that the best place for a smoke alarm is not always the best place for a CO alarm. A combo alarm in a hallway outside bedrooms is usually ideal for both, but a smoke alarm inside a basement stairwell or high on a vaulted ceiling may not be the best CO location. Our carbon monoxide detector guide covers the CO side in detail.

Smoke alarms are also not air quality monitors. If you worry about wildfire smoke or cooking particles in the air you breathe, a PM2.5 monitor tells you far more; see our guide to the best air quality monitors for home, and if smoke from outside gets in during fire season, the best air purifier for smoke is the tool that actually cleans it.

Maintenance, False Alarms and Replacement

Test every month

NFPA and the U.S. Fire Administration both recommend testing smoke alarms at least once a month using the test button. The test confirms the horn, electronics and battery work. It takes 10 seconds per alarm, and with interconnected alarms, pressing one test button should set off all of them, which checks the interconnect at the same time.

Make sure everyone in the home knows the sound of the alarm and what to do. The U.S. Fire Administration warns that you may have less than 2 minutes to get everyone outside once an alarm sounds, so a practiced escape plan with two ways out of every room matters as much as the alarm itself.

Pick a fixed routine, such as the first Saturday of each month. For replaceable-battery alarms, change the batteries at least once a year, and use only the battery types listed on the back of the alarm, since NFPA notes the alarm may not work properly with a different kind.

Cleaning and preventing dust problems

Dust, cobwebs and insects inside the sensing chamber can trigger false alarms or slow detection. Follow the manufacturer’s cleaning instructions, which usually mean vacuuming around the vents with a soft brush attachment every few months, without opening the alarm.

Renovation dust is a special case. Drywall sanding and sawing can contaminate a sensor quickly, so cover alarms with the dust cap supplied by some manufacturers or a plastic bag while you work, and remove it the same day. A covered alarm cannot detect a fire.

Never paint an alarm, and do not mount it where cooking grease, steam or shop dust will coat it. If an alarm keeps false-alarming after cleaning, move it farther from the source or replace it with a newer, current-standard model.

Chirps, hush buttons and what never to do

A single chirp that repeats at regular intervals usually means a low battery, and on a sealed-battery alarm, it often means end of life. NFPA advises that when a 10-year sealed alarm chirps for low battery, you replace the entire alarm right away. Some alarms use different chirp patterns for end of life, so check the manual.

When cooking or steam sets off an alarm, the U.S. Fire Administration says to open a window or door, press the hush button and wave a towel to clear the air. Hush buttons silence the alarm for a few minutes and then rearm it automatically.

Never remove the battery or disconnect a hardwired alarm to stop a nuisance alarm. According to NFPA, 16% of home fire deaths from 2018 to 2022 happened in homes where smoke alarms were present but failed to operate, and missing or disconnected power sources were the most common reason.

Replace every 10 years

Every smoke alarm has a manufacture date printed on the back. The U.S. Fire Administration says alarms must be replaced 10 years from that date, whether the alarm is battery, sealed or hardwired, because sensors degrade with age even if the test button still sounds the horn. The test button checks the electronics, not how well the sensor responds to real smoke.

If you find alarms in your home that are more than 10 years old, replace them now and consider replacing the whole interconnected set at once. That also moves your home to current-standard alarms with the 8th edition cooking test and faster fire response.

Write the installation date on the alarm or in a household maintenance log. Pair smoke alarm replacement with other periodic safety tasks, such as changing HVAC filters, which our HVAC filter and MERV rating guide covers.

Frequently Asked Questions

What smoke detector do firemen recommend?

Fire service organizations such as NFPA and the U.S. Fire Administration do not endorse brands, but they recommend alarms that carry the label of a recognized testing laboratory, installed in every bedroom, outside each sleeping area and on every level, and interconnected. USFA recommends having both ionization and photoelectric sensing, either as separate alarms or as dual-sensor units.

What is the most reliable smoke detector?

The most reliable setup is hardwired alarms with battery backup: NFPA found hardwired alarms operated in 94% of fires large enough to trigger them, compared with 85% for battery-only alarms. For a single alarm, choose one certified to UL 217 8th edition or newer with a sealed 10-year battery or 10-year backup, such as the Kidde 20SA10-V or X-Sense SC07.

Which brand makes better smoke detectors?

Between Kidde and First Alert, neither brand is clearly better; both make UL 217 certified alarms built to the new standard, and both are widely recommended. The most important factor is compatibility: interconnected alarms usually need to come from the same brand, so match your existing system, First Alert with First Alert or BRK, and Kidde with Kidde.

Are hardwired smoke detectors better than battery ones?

Yes, when the wiring exists. NFPA data shows lower death rates with hardwired alarms, largely because they do not depend on someone replacing batteries. If your home has no alarm wiring, sealed 10-year battery alarms with wireless interconnect are the best alternative.

Which smoke detector has the fewest false alarms?

Alarms built to the UL 217 8th edition or newer must pass a cooking nuisance test, and photoelectric alarms are generally less prone to cooking false alarms than older ionization models. NIST testing found new alarms can still sound during cooking, so placement at least 10 feet, and ideally 20 feet, from the stove matters as much as the model.

How often should smoke detectors be replaced?

Replace smoke alarms 10 years from the manufacture date printed on the back, according to the U.S. Fire Administration. Replace 9-volt or AA batteries at least once a year, and replace a sealed-battery alarm as soon as it gives a low-battery or end-of-life chirp.

Do I need a combination smoke and carbon monoxide detector?

You need CO protection if your home has any fuel-burning appliance, a fireplace or an attached garage, and a combination alarm is a convenient way to get it in hallways outside bedrooms. Make sure it is certified to both UL 217 and UL 2034, and add separate CO alarms where the placement rules differ.

Is a smart smoke detector worth it?

A smart alarm is worth it if you want phone alerts when no one is home, low-battery warnings without chirps or the option of professional monitoring. It does not detect fire any better than a certified standard alarm, so interconnection and correct placement still come first.

For the carbon monoxide side of home safety, see our best carbon monoxide detectors guide, and for the air you breathe every day, our picks for the best air quality monitors for home.

Written by the Delozone Editorial Team. We research products using manufacturer specifications, certification listings, NFPA, NIST and U.S. Fire Administration guidance and verified owner feedback, and we update guides when products or standards change. How we work.