How Smart Smoke Detectors Work and How to Set One Up

Traditional smoke detectors beep loudly when they detect smoke or carbon monoxide — but only if you are home to hear them. A smart smoke detector does everything a regular one does, plus it sends an alert to your phone no matter where you are. If a smoke alarm goes off while you are at the grocery store or visiting family, you will know immediately and can call for help.

Two of the most popular smart smoke detectors in the US are the Google Nest Protect and the First Alert Onelink Safe and Sound. Both connect to your home Wi-Fi and pair with a phone app. Both detect smoke and carbon monoxide. The Nest Protect is well regarded for its friendly voice announcements — instead of only beeping, it tells you "There is smoke in the hallway" so you know where to look.

Installing a smart detector works similarly to replacing any smoke detector. Turn off power to the circuit if you are replacing a hardwired unit, or remove the old battery-powered detector. Mount the new smart detector to the ceiling using the included hardware — most require only two screws and a mounting bracket. Hardwired models connect to the existing wiring in your ceiling.

After mounting, download the corresponding app — the Nest app (or Google Home app) for Nest Protect, or the First Alert Onelink app for Onelink products. Open the app and follow the pairing steps, which involve connecting the detector to your home Wi-Fi. Once connected, you can name the device ("Living Room Smoke Detector") so alerts clearly identify which one triggered.

The app will notify you on your phone whenever the detector sounds, identifies what it detected (smoke vs. carbon monoxide), and which room the alarm came from if you have multiple units. You can also silence a false alarm from the app — no more waving a towel at the ceiling.

Smart detectors also handle maintenance reminders proactively. The app notifies you when the battery is getting low and when the sensor inside the unit should be replaced (typically after 10 years). Monthly self-tests run automatically, so you do not have to remember to push the test button.

If you install multiple smart detectors, they can be interconnected — when one goes off, all of them sound simultaneously, which is important in larger homes.