First Alert smoke and carbon monoxide alarms

The reports, as CPSC published them

1. No incident, no one hurt

   Made Sep 17, 2026 · , sent to the company Sep 22, 2026 · , published by CPSC Oct 6, 2026

   The product, in the report: First Alert SMCO210V combination smoke and carbon monoxide alarm. The alarms are white, residential-use units designed to detect smoke/fire and carbon monoxide. I have two units, both purchased together as a two-pack from Home Depot. Both units have a manufacture date of July 11, 2024. The model number printed on the alarms is SMCO210V. Both are the same model and appear identical in size and design.

   I am reporting a possible safety issue involving two First Alert SMCO210V combination smoke and carbon monoxide alarms that I purchased together as a two-pack from Home Depot. Both alarms have a manufacture date of July 11, 2024.

   The first alarm began repeatedly going into a fire alarm in 2025 even though there was no apparent fire or smoke. This happened at least twice, and possibly three times, with the incidents occurring days apart. After one of the incidents, either the fire department or DTE Energy came out and checked the situation, and carbon monoxide was ruled out. There was no apparent fire, smoke, unusual smell, or other obvious cause for the alarm.

   Approximately a month later, the second alarm from the same two-pack experienced essentially the same problem. It went into a fire alarm in the middle of the night. Nobody was downstairs at the time, and nothing was running in the area. Again, there was no apparent fire, smoke, unusual smell, or other obvious explanation.

   The alarms were being used as residential smoke and carbon monoxide detectors as intended. No one was injured as a result of the incidents, but I am concerned about the safety implications of a smoke alarm repeatedly giving a false fire alarm. A false alarm could also potentially cause a real alarm to be disregarded in the future.

   I still have both alarms. I am reporting the issue because both units from the same two-pack independently experienced essentially the same problem.

   Model

   SMCO210V

   UPC

   029054022264

   Bought from

   Home Depot

   Bought

   Dec 10, 2024, about then

   Where

   Farmington Hills, Michigan: Home/Apartment/Condominium

   Who was involved

   Age 1, Unknown

   The reporter’s relation to them

   Self

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   No Incident, No Injury

2. No incident, no one hurt

   Made Aug 27, 2026 · , sent to the company Sep 2, 2026 · , published by CPSC Sep 17, 2026

   The product, in the report: First Alert SC5 Hardwire Smart Smoke and Carbon Monoxide Alarm SMCO600NV-AC

   First Alert SC5 smoke detector units failed after 4-6mo and produce constant false alerts, leading consumers to deactivate alarms.

   Model

   SMCO600NV-AC

   Bought from

   Best Buy

   Bought

   Oct 15, 2025, about then

   Where

   Washington, District of Columbia: Home/Apartment/Condominium

   Who was involved

   Age 7, Unspecified

   The reporter’s relation to them

   My Child

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   No Incident, No Injury

3. No one hurt

   Made Aug 15, 2026 · , sent to the company Aug 19, 2026 · , published by CPSC Sep 3, 2026

   The product, in the report: Product name: First Alert SC5 Smart Smoke & Carbon Monoxide Alarm, hardwire Manufacturer: Resideo Technologies, Inc. (First Alert brand) Model number: SMCO600NV-AC (retail SKU FSMCO600NVACCL1)

   Three First Alert SC5 hardwired smoke and carbon monoxide alarms were installed in a three-level single-family dwelling in July 2025, replacing expiring [REDACTED] units. Over the following thirteen months two of the three produced repeated false smoke alarms at least 31 smoke notifications and 8 full alarm activations, none corresponding to any fire, smoke or hazardous condition.

   The safety risk is twofold. First, the alarms cannot reliably be silenced. On two separate occasions, under two different interconnect configurations, an activated SC5 could not be silenced by any means available to a person physically present. On both occasions the only way to stop the alarm was to take the units down from the ceiling and remove their batteries. The second occasion, on July 28, 2026, involved a neighbour attending an unoccupied property who had to dismantle all three units. As a direct result the dwelling was left with no functioning smoke or carbon monoxide detection on any of its three levels for a period. A life-safety device that can only be stopped by dismantling it compels its own disablement, which is the recognised pathway to fatal outcomes in residential fires.

   Second, one unit shows evidence of an abrupt sensor or signal-processing fault. The SC5 issues a “Heads-Up Smoke Warning” when obscuration is rising, ahead of full alarm. The second-floor unit produced three full alarms January 16, January 17 and July 12, 2026 with no preceding warning on any occasion. Smoke does not appear instantaneously. A device that transitions from quiescent to full alarm without detecting any rise raises the converse concern: whether its sensor reports the true state of the room in either direction.

   Two of these false alarms occurred while the property was closed and unoccupied between June 24 and August 14, 2026, with no person present and no possible smoke source. One ran and cleared entirely on its own, with no intervention recorded in the manufacturer’s own activity log.

   The complete event record is documented by 35 automated notification emails from the manufacturer’s own alert system, plus the First Alert app activity feed. Both are retained and available. The manufacturer has been notified separately.

   This model is marketed as meeting UL 217 9th Edition and as equipped with technology to reduce nuisance alarms, and is promoted by both Resideo and [REDACTED] as the designated replacement for the discontinued [REDACTED], meaning it is being installed in large numbers in homes currently reaching end-of-life on those units. Published consumer reviews for both SKUs describe the same failure pattern in substantial numbers, including cases where warranty replacement units behaved identically.

   Model

   SMCO600NV-AC

   Bought from

   firstalert.com

   Bought

   Jul 8, 2025

   Where

   Greece: Home/Apartment/Condominium

   Who was involved

   Unknown

   The reporter’s relation to them

   Unspecified

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   Incident, No Injury

4. No one hurt

   Made Jul 21, 2026 · , sent to the company Jul 24, 2026 · , published by CPSC Aug 7, 2026

   The product, in the report: First Alert SC5 hardwired combination smoke and CO alarms (model SMCO600NV-AC, retail SKU FSMCO600NVACCL1)

   I am a professional firefighter with fifteen years of service. I am reporting a pattern of defective behavior in First Alert SC5 combination smoke and carbon monoxide alarms installed in my own residence.

   I purchased six First Alert SC5 hardwired combination smoke and CO alarms (model SMCO600NV-AC, retail SKU FSMCO600NVACCL1) from Best Buy on July 1, 2025, delivered July 3, 2025. All six units carry the same manufacture date code, 2025 JUN 13, indicating a single production batch. Recorded unit identifiers include MAC IDs [REDACTED] and [REDACTED].

   These alarms replaced six [REDACTED] alarms that operated in the same rooms, on the same household wiring, using the same ceiling boxes, for approximately ten years. In that decade the [REDACTED] units produced zero false alarms and zero connectivity failures.

   Since installation, the SC5 alarms have entered full alarm state repeatedly with no smoke, fire, or carbon monoxide present. Events have been recorded in the First Alert app activity log.

   At the time of each event there was no cooking, no shower steam or elevated humidity, no dust, and no sanding, painting, demolition, or renovation activity in the residence. Multiple events occurred overnight with the household asleep. Alarms have originated from units in at least four separate locations in the home.

   The alarms have also repeatedly lost network connectivity, dropping offline and returning without explanation despite running a top-of-the-line Router with perfect signal strength, and no other smart devices experiencing such issues.

   Separately, the First Alert app’s alarm screen instructs the user to mute the siren and dismiss the alert if the alarm is false, but the Mute Siren control is non-functional during these events. I have screenshots. This means a known-false alarm cannot be silenced from the app as the product’s own interface directs.

   I have also observed inconsistent unit attribution within the app. For one event, the activity feed identified one alarm as the detecting device while the alert detail screen identified a different alarm. Location-specific alerting is a headline advertised feature of this product.

   I want to note a further deficiency directly relevant to this report. The First Alert app retains only approximately ninety days of activity history and provides no means of exporting it. My units have been in service since July 2025, but the app shows me nothing before April 2026. The log I am submitting is therefore a partial record covering roughly the last quarter, and it already contains multiple false-alarm events. The full record is worse and I cannot produce it. For a connected life-safety device, an owner should not be structurally unable to document a fault pattern, substantiate a warranty claim, or provide event records to a fire investigator. Resideo holds the complete server-side event history for these units and I am requesting it from them.

   HAZARD: I am reporting this as a fire service professional. The hazard here is not the noise. It is habituation. Repeated false activation trains occupants - especially children - to assume that any alarm is false and to delay or skip evacuation. In my career I have seen the consequences of delayed egress. My own children have now been woken repeatedly by these alarms and have begun responding to alarm activation by assuming it is another malfunction. This product has actively degraded the fire response behavior of a household in which fire safety is taken seriously. That is the opposite of what a life-safety device is for.

   The secondary hazard is disablement. Owners experiencing repeated overnight false alarms predictably remove batteries or take units down, leaving homes unprotected. Public reviews of this model show owners doing exactly that.

   No injury or property damage has occurred. All six units remain installed, in service, and in my possession. None have been modified, disassembled, or altered, and installation followed the manufacturer’s instructions using the manufacturer’s supplied quick-connect harness.

   I request that CPSC review this model for a defect pattern. I am aware of at least one prior incident report on this model from another fire service officer describing complete unit failure, repeated false alarms, and the failure of a manufacturer-supplied warranty replacement unit within approximately three weeks.

   Model

   SMCO600NV-AC

   Serial number

   [REDACTED]

   Bought from

   Best Buy

   Bought

   Jul 1, 2025

   Where

   Grove City, Ohio: Home/Apartment/Condominium

   Who was involved

   Unspecified

   The reporter’s relation to them

   Unspecified

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   Incident, No Injury

5. No one hurt

   Made Jul 16, 2026 · , sent to the company Jul 21, 2026 · , published by CPSC Aug 4, 2026

   The product, in the report: First Alert SC5 Hardwire Smart Smoke & Carbon Monoxide Alarm, SMCO600NV-AC

   A First Alert SC5 Hardwire Smart Smoke & Carbon Monoxide Alarm, SMCO600NV-AC is initiating false alarms, indicating that there is heavy smoke in our home when there is no smoke at all. Further, the alarm failed to silence via the app or via touching the silence button on the unit. It indicated that the smoke level was too high to allow for silencing. While the smoke alarms around our house wailed at full volume at 2am, a frantic search for a ladder was necessary to pull the unit from the wall, creating a dangerous situation with a high likelihood of injury and exposing me to high levels of sound during the process of unplugging the unit and removing the batteries. Further investigation into online reviews of this product indicate that this is a common occurrence and that the company has failed to rectify the issue with false alarms.

   Model

   SMCO600NV-AC

   Bought from

   Amazon

   Bought

   Dec 8, 2025

   Where

   Ithaca, New York: Home/Apartment/Condominium

   Who was involved

   Age 43, Unknown

   The reporter’s relation to them

   Self

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   Incident, No Injury

6. No one hurt

   Made Jun 9, 2026 · , sent to the company Jun 11, 2026 · , published by CPSC Jun 29, 2026

   The product, in the report: The First Alert SC-5 is the replacement for the [REDACTED]. It is a combination Smoke CO2 alarm with WiFi, [REDACTED] and a phone app by Resideo

   I had [REDACTED] Smoke/CO2 alarms (11 of them) for 10 years and they performed flawlessly. I especially appreciated the alarm annunciation which indicated which of the alarms detected the smoke/CO2 to save time pinpointing the emergency location in my home. Then [REDACTED] killed the [REDACTED] alarm range and the 10yr life span from my installation expired. The [REDACTED] recommended replacement was the First Alert SC-5 Smoke/CO2 alarm. I dutifully replaced them all (@$129 each) hardwired with 120VAC using the included wiring adapter.

   5 FALSE ALARMS IN THE LAST WEEK WITH 2 COMING IN THE MIDDLE OF THE NIGHT!!!!!

   WHAT UTTER JUNK THE SC-5 ALARM IS compared to the [REDACTED]. 90% of the time it goes off is for quite literally no damn reason - false alarms. Tonight it went off twice at 3AM and 4:30AM for ZERO reason. No windows open all day (not pollen), and humidity 43% (not humidity). This has happened multiple times. I have even arrived home to find the alarms blaring for no discernable reason. These alarms are a NIGHTMARE compared to [REDACTED]! There is no confidence in the system and my family is getting upset.

   SC-5 issues false alarms for quite literally no reason, no smoke, no haze, nothing, it just decides to wake the whole house up and ruin everyone’s sleep with a false no Smoke/CO2 condition. [REDACTED] NEVER did that in the 10yrs I owned them.

   There are so many false positive alarms that we just assume now that every event it is a false alarm. This means that if there were a real fire, we could not be sure without policing the entire 4 story house. In fact it is so common the @firstalert @resideo app has become “the boy who cried “Wolf!”! (Lawsuit: if there is a fire but we are being conditioned to ignore it because of incessant false alarms).

   5. As a lower priority, the motion activated “night light” was a wonderful [REDACTED] feature. If one gets out of bed at night, the [REDACTED] would light the way. Sadly, the @FirstAlert did not attend to this feature, they stripped that useful offer requirement.

   I don’t know which engineering team developed the [REDACTED] SC-5 integration but obviously they did not replicate the sensible design of the [REDACTED], it’s not even close. In fact, I am not even sure qualified experts even reviewed the system design for feature comparison with the [REDACTED], much less the reliability of the [REDACTED] and the confidence it inspired.

   I may also be speaking for a lot of other sleepless and very angry customers using the same system.

   Fix the SC-5 by pushing a FW update with a bugfix, find a replacement, or give me my $1,419.00 ($129 x 11) back so I can start over with another system. 6 months in and I already hate it and have low confidence in the system.

   Model

   SC-5

   Serial number

   I have 11 alarms. All have the same problem.

   Bought from

   First Alert Store

   Bought

   Apr 3, 2026, about then

   Where

   PELHAM, New Hampshire: Home/Apartment/Condominium

   Who was involved

   Unknown

   The reporter’s relation to them

   Unspecified

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   Incident, No Injury

7. No one hurt

   Made Sep 6, 2025 · , sent to the company Sep 10, 2025 · , published by CPSC Sep 24, 2025

   The product, in the report: Combination smoke/CO2 alarm First Alert SC5 hardwired wi-fi enabled unit.

   Combination smoke/CO2 alarm alerts with multiple false positives. Replaced units multiple times and issue is ongoing. Other brand unit, [REDACTED], does not alert same location.

   Model

   FSMC0600NVACCL1

   UPC

   194160013717

   Serial number

   5CFCE1907411

   Bought from

   firstalert.com

   Bought

   Jun 11, 2025

   Where

   N Andover, Massachusetts: Home/Apartment/Condominium

   Who was involved

   Unspecified

   The reporter’s relation to them

   Unspecified

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   Incident, No Injury

8. No one hurt

   Made Aug 24, 2025 · , sent to the company Aug 26, 2025 · , published by CPSC Sep 10, 2025

   The product, in the report: First Alert Smoke and Carbon Monoxide Alarm

   First Alert Smoke and Carbon Dioxide Alarm cover appears to have burned and melted from internal heat.

   Model

   Model # ZCOMBO

   Where

   Troy, Michigan: Home/Apartment/Condominium

   Who was involved

   Unspecified

   The reporter’s relation to them

   Unspecified

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   Incident, No Injury

9. No incident, no one hurt

   Made Jul 26, 2025 · , sent to the company Jul 30, 2025 · , published by CPSC Aug 13, 2025

   The product, in the report: First Alert one link fire and co2 alarm wired and battery

   In October 2024, this First Alert Onelink for alarm that is smart, wired, battery went defective and started chirping even though it had new batteries. We called company and they said to “blow out the unit” with an aircan. It seemed to help. But on Sunday, July 20, 2024 at 3am, the unit went off as if we had a fire in that area, the basement. My husband had to deactivate the alarm to get out to stop, leaving us without a wired alarm in that area. Even after deactivating, the unit kept going off . The company sent us three new units, took 5 days.

   Model

   1042135

   UPC

   Na

   Serial number

   1042135

   Where

   CANTON, Michigan: Home/Apartment/Condominium

   Who was involved

   Age 19, Unspecified

   The reporter’s relation to them

   My Child

   As this report names them

   Brand First Alert, made or sold by BRK Brands, Inc

   How badly, in CPSC’s words

   No Incident, No Injury

10. No one hurt

    Made Jul 16, 2025 · , sent to the company Jul 21, 2025 · , published by CPSC Aug 4, 2025

    The product, in the report: First Alert Model SMCO210V Smoke and Carbon monoxide Alarm

    First alert Smoke and CO detector alarms without cause. I have 5 of these units and two alarm indicating there is a CO issue but report zero ppm of CO (these are talking monitors). I do not have any CO producing devices running in my home. I have moved the devices to various locations and only two of them alarm, regardless of their location. The other three devices never alarm despite being in the same locations as those that do alarm. I feel this is a danger in that it requires people to disable a malfunctioning Smoke and CO detector when they may not have a substitute device available. This has happened over the last week. The first device alarmed and was replaced, the replacement ( I had an extra available, new in the box and unactivated) started alarming a few days later. Both have a manufacturing date of 2024 JUL 11 - L23

    Model

    SMCO210V

    Serial number

    NA

    Bought from

    Amazon

    Bought

    Sep 18, 2024, about then

    Where

    Foster, Rhode Island: Home/Apartment/Condominium

    Who was involved

    Unspecified

    The reporter’s relation to them

    Unspecified

    As this report names them

    Brand First Alert, made or sold by Ademco Inc.

    How badly, in CPSC’s words

    Incident, No Injury

11. No one hurt

    Made Aug 24, 2023 · , sent to the company Aug 28, 2023 · , published by CPSC Sep 12, 2023

    The product, in the report: First Alert Model No PC1210 Combination Smoke Detector and CO Alarm

    I have purchased several First Alert Smoke Detectors around 9/26/2022. Once they were installed in my house, they began to malfunction. The units beep until I Deactivate them. This began happening about 2 months ago and has happened again last month and most recently yesterday.

    Model

    PC1210

    Serial number

    3055574

    Bought from

    Lowes

    Bought

    Sep 26, 2022, about then

    Where

    United States: Home/Apartment/Condominium

    Who was involved

    Unspecified

    The reporter’s relation to them

    Unspecified

    As this report names them

    Brand First Alert, made or sold by BRK Brands, Inc

    How badly, in CPSC’s words

    Incident, No Injury

12. No one hurt

    Made Apr 22, 2023 · , sent to the company Apr 26, 2023 · , published by CPSC May 10, 2023

    The product, in the report: FIRET ALERT HARDWIRED SMOKE AND CARBON MONOXIDE ALARM W/ VOICE & LOCATION (white)

    First Alert smoke and CO2 detector sounds the alarm when the batteries are low rather than giving off a chirp. This is causing distress to people in the household and pets. The alarms will randomly go off in the middle of the night causing a panic of a fire while the batteries just need to be changed in the detector. I scramble to take out the batteries and put new ones in when this occurs but it doesn’t stop the alarm immediately and continues for several minutes. There is no way to stop this from happening, as it has occurred for years, when it’s time to change the batteries. I feel like a product like this should be on the market as other detectors with chirping when batteries are low is highly effective and inconsequence in comparison to the automatic random alarm blasts of the First Alert product.

    Model

    SC7010BV

    Where

    Winooski, Vermont: Home/Apartment/Condominium

    Who was involved

    Unspecified

    The reporter’s relation to them

    Unspecified

    As this report names them

    Brand First Alert, made or sold by Ademco Inc.

    How badly, in CPSC’s words

    Incident, No Injury

13. No incident, no one hurt

    Made Aug 31, 2022 · , sent to the company Sep 13, 2022 · , published by CPSC Sep 27, 2022

    The product, in the report: First Alert Smoke and Carbon Monoxide detectors. Model number SCO500

    I purchased 4 First Alert Smoke and Carbon Monoxide Detectors from Target on 5/21/22. I purchased these because they are battery operated and interconnected and you can program them so you know where the issue is in your house. They have gone off 4 times in the last 3 weeks for no reason. When they trigger they just have the alarm, there is no talking to say fire or CO. They also do not tell me where in the house the issue is. I paid $250.00 with the protection plan . The protection plan won’t cover them since they are under a year. Target won’t take them back because it is just over 90 days. I spoke with First Alert and they won’t refund the money but will replace 3 of the 4. If it happens again they will replace the 4th. They are shipping them to me and it will take 7 - 10 days to get them. I know have to purchase smoke alarms today since I’m not going 7-10 days without protection. There is something wrong with the product and it should be recalled. I paid a lot for these for the protection of them all going off and telling me where the issue is in my house. They do not act as advertised. It will do it if you test them, but only when you are testing them. So the manufactures says they are fine and they are not.

    Model

    SCO500B

    UPC

    n/a

    Serial number

    n/a

    Bought from

    Target

    Bought

    May 22, 2022, about then

    Where

    Pawtucket, Rhode Island: Home/Apartment/Condominium

    Who was involved

    Age 52, Male

    The reporter’s relation to them

    Self

    As this report names them

    Brand First Alert, made or sold by BRK Brands, Inc

    How badly, in CPSC’s words

    No Incident, No Injury

CPSC’s disclaimer

Sources