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Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Google has discontinued Nest Protect sales and now directs owners to First Alert’s SC5 Smart Smoke and Carbon Monoxide Alarm. The SC5 is designed to work with the Google Home app and can coexist with compatible Nest Protect alarms, but it is a First Alert product—not a new Google-branded Nest Protect and not a guaranteed one-for-one replacement for every Nest feature.
What changed on the Google Store?
The Nest Protect product page remains online, but the alarm is marked “No longer available.” Google’s page also says Nest Protect sales have been discontinued and points customers toward First Alert’s Smart Smoke and Carbon Monoxide Alarm as the replacement: Google Store Nest Protect page.
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First Alert Battery Smoke Alarm | SMI100 | $16.99 | Buy on Amazon |
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Kidde Compact Smoke Detector, AA Battery-Powered, 10SDR | $18.97 | Buy on Amazon |
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SITERWELL Smoke Detector, 10 Year Product Life Fire Alarm | $89.81 | Buy on Amazon |
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First Alert Battery Smoke Alarm | SMI100 | $49.97 | Buy on Amazon |
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This is different from a temporary stock shortage. Some older configuration pages may still display Nest Protect variants as “out of stock,” but Google’s product page identifies the product as discontinued rather than promising new inventory.
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Google is not selling a new successor under the Nest Protect name. It is directing customers to First Alert’s SC5 range.
#1 Best Overall
- First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.
- Battery-operated alarm allows for easy installation and maintenance
- Front access battery compartment makes for easy battery replacements
- End-of-life warning lets you know when it’s time to replace the alarm
- Test/silence button for efficient testing to ensure alarm is working properly
When was Nest Protect discontinued?
On March 28, 2025, Google announced that it was ending new Nest Protect production. Remaining units were to be sold while supplies lasted. Google also said existing Protect alarms would continue working through their expiration dates and continue receiving software and security updates under the existing support policy. See Google’s Nest Protect discontinuation announcement.
Discontinued sales therefore do not mean that every installed Nest Protect stopped working immediately. Owners should still check the alarm’s manufacture date and replacement warning rather than relying only on whether it appears online.
The official replacement: First Alert SC5
Google and First Alert identify the SC5 as the compatible replacement for an expiring second-generation Nest Protect in the United States and Canada.
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A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11| Version | First Alert model | Best suited to |
|---|---|---|
| SC5 Battery Smart Smoke and Carbon Monoxide Alarm | FSMCO600NVCL1 | Battery-powered installations |
| SC5 Hardwire Smart Smoke and Carbon Monoxide Alarm | SMCO600NV-AC | Homes with compatible hardwired alarm circuits |
The SC5 provides smoke and carbon-monoxide detection, smartphone alerts, smart-home integration through Google Home, and interconnected-alarm functionality according to First Alert’s product and compatibility information. First Alert also says the SC5 can work with existing Nest Protect alarms through the Google Home app and a Google Account. Details are available on First Alert’s Nest Protect replacement page and compatibility list.
Rank #2
- First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency
- Battery-operated alarm allows for easy installation and maintenance
- Front access battery compartment makes for easy battery replacements
- End-of-life warning lets you know when it’s time to replace the alarm
- Test/silence button for efficient testing to ensure alarm is working properly
Does the SC5 replace Nest Protect feature-for-feature?
It should be treated as a compatible replacement, not an identical recreation of Nest Protect.
| Capability | Nest Protect | First Alert SC5 |
|---|---|---|
| Smoke detection | Yes | Yes |
| Carbon-monoxide detection | Yes | Yes |
| Google Home integration | Yes | Yes, according to Google and First Alert |
| Battery and hardwired choices | Yes | Yes |
| Mixed installation with compatible Nest Protect alarms | Original platform | Supported according to First Alert, using Google Home |
| Pathlight, Nightly Promise and Sound Check | Nest-specific features | Do not assume equivalent operation |
| Brand | Google Nest | First Alert |
Google’s current material discusses Nest Protect functionality in Google Home, but that does not establish complete parity with the discontinued hardware. Do not assume that the SC5 duplicates Nest Protect’s voice prompts, room-location experience, Nightly Promise, Pathlight, Sound Check, Nest app controls, or every Nest-specific automation. See Google’s Google Home guidance for Nest Protect for the platform’s current functionality.
When must an existing Nest Protect be replaced?
Google says a second-generation Nest Protect must be replaced 10 years after its manufacture date to meet certification requirements. The carbon-monoxide sensor has a limited service life, and the alarm provides end-of-life warnings. The replacement date is based on manufacture—not the day the alarm was installed.
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1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesConnected owners may receive reminders when the Protect is linked to Wi-Fi and set up in the Nest or Google Home app. An expired or failed unit should not be treated as a fully dependable smoke and CO alarm. Follow Google’s expiration guidance.
Rank #3
- SMOKE DETECTION: Model 10SDR detects smoke with over 25% faster smoke detection*; sounds a loud 85-decibel alarm with red LED light for clear visual warnings; compact design suitable for homes
- AA BATTERY OPERATION & WARRANTY: Powered by two AA batteries (included) for easy, no-wiring setup; backed by 10-year limited warranty** that starts from date of purchase
- REDUCED FALSE ALARMS: Uses advanced sensing technology that helps distinguish between real smoke and everyday cooking or steam; helps reduce false alarms while maintaining quick, accurate detection when smoke is present
- TESTED FOR RELIABILITY & COMPLIANCE: Rigorously tested to meet UL 217 10th Edition and FCC standards; helps ensure compliance with recognized safety requirements and consistent performance in residential environments
- BUILT FOR HOMEOWNERS AND PROFESSIONALS: Designed for those who prioritize dependable, code-compliant detection; supports safety goals for homeowners, property managers, contractors, and professionals seeking long-term home safety assurance
How to choose the correct SC5 model
Choose the battery model when:
- The existing Nest Protect is battery-powered.
- No mains alarm wiring is present.
- You want to avoid electrical work, subject to local placement and fire-code requirements.
Choose the hardwired model when:
- The existing alarm is connected to a compatible hardwired circuit.
- The replacement complies with the home’s electrical and fire-code requirements.
- The wiring and interconnect arrangement have been verified before installation.
The battery and hardwired SC5 models are not interchangeable simply because both support Google Home. A hardwired alarm must match the existing circuit and installation requirements. If you are not comfortable working on mains wiring, use a qualified electrician.
Installation and replacement guidance
Google’s documented replacement flow is to confirm that the Nest Protect needs replacement, select the appropriate replacement device, remove the old alarm, then install and set up the new alarm using its manufacturer’s manual: Google’s replacement instructions.
For a battery Nest Protect
- Turn the Protect counterclockwise to remove it.
- Unscrew and remove the backplate.
- Install and configure the SC5 according to the First Alert instructions.
For a hardwired Nest Protect
- Turn off power at the breaker before touching the alarm or wiring.
- Turn the Protect counterclockwise to remove it from the backplate.
- Unplug the 120-volt connector.
- Remove the backplate if required.
- Install the correct SC5 hardwired model and follow its wiring instructions.
First Alert says the SC5 can use the same mounting bracket when replacing a Nest Protect and that a quick-connect adapter plug is included for hardwired replacements. This can simplify the physical swap, but a shared bracket does not by itself prove that every wiring arrangement is code-compliant. Follow the SC5 manual, verify interconnect compatibility, maintain compliant alarm placement, and test every alarm after installation.
Mixed Nest Protect and SC5 installations
Keeping some unexpired Nest Protect alarms while adding SC5 units may be practical. First Alert specifically documents Nest Protect battery and wired models as compatible alarms for the SC5 system. Google Home and a Google Account are required for Nest Protect compatibility.
Rank #4
- 【10-Year Product Life】The smoke detector has 1-year 9V battery. This smoke alarm can be used for ten years with continuous battery replacement. Working smoke detector cut the risk of dying in a home fire by 50% while a home fire starts every 83 seconds! The faster you realize a fire warning, the more time to escape from the fire
- 【Photoelectric Technology】The GS509A is a photoelectric smoke alarm. The photoelectric technology, it is more sensitive in detecting slow smoldering fires which generate light smoke, little heat and may smolder for hours before bursting into flames
- 【Test/Mute Button】The smoke detector is designed to test the normal operation of the product by pressing the test button. Weekly testing is required. The product is designed to be silent and not disturb your rest
- 【Humanized Design】Loud>85dB makes everyone in the house can hear the alarm clearly when the smoke alarm is chirping. If low battery there will be a signal alarm, which informs you to change a new battery
- 【Easy Installation&High Quality】The fire detector can be easily installed through the mounting bracket. It can be easily mounted on the wall or ceiling. this equipment is installed in accordance with the NFPA standard 72, so you can rest assured and absolutely trust our products
After setup, confirm that:
- All alarms are linked to the intended Google account.
- Google Home recognizes both the existing Protect units and the SC5.
- Interconnected alarms sound together when tested.
- Each alarm remains correctly positioned under applicable local requirements.
Compatibility should not be interpreted as identical app behavior or identical alarm features across the two products.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Price and availability
First Alert’s official pages displayed a listed price of $129.99 for both SC5 variants when checked on August 18, 2026. Those pages also showed the battery model as unavailable or backordered and the hardwired model as unavailable in the catalog. Prices and stock can change, so treat those figures as a dated price signal rather than a guaranteed offer:
A Google Store link to the replacement therefore does not guarantee immediate availability.
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When a conventional alarm may be the better choice
The SC5 makes the most sense for owners who value Google Home integration, smartphone alerts, and continuity with existing compatible Nest Protect alarms. It may not be the right choice if stock is unavailable, the price is unacceptable, or smart-home features are not important.
Best Value
- First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency
- Battery-operated alarm allows for easy installation and maintenance
- Front access battery compartment makes for easy battery replacements
- End-of-life warning lets you know when it’s time to replace the alarm
- Test/silence button for efficient testing to ensure alarm is working properly
First Alert also lists conventional combination smoke and CO alarms, including battery and hardwired options. These may cost less, but they do not offer the same Google Home smart-alert proposition. Compare certification, power type, interconnect method, replacement interval, local code compliance, and availability—not just whether an alarm carries the First Alert name:
Other certified alarm systems are also reasonable if you are willing to leave the Google Home ecosystem or standardize every alarm on a different interconnect platform. Do not assume that any First Alert alarm is a Google Home-compatible Nest Protect replacement; the SC5 is the model documented for that role.
Geography matters
The Google and First Alert replacement information covered here specifically identifies U.S. and Canadian versions. Readers in the United Kingdom, Europe, or elsewhere should separately verify local availability, electrical standards, certification, app support, and installation requirements before buying. The SC5 should not be presented as a universally available replacement.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
