HomeKit-enabled Smoke Alarm [OneLink Review]

Last Updated: Jul 01, 2021

Written by

This article contains affiliate links, which means that I may receive a commission if you make a purchase using these links.

First Alert recently released Onelink; an Apple HomeKit enabled smoke alarm. I took that as an opportunity to get my feet wet with HomeKit and to start equipping our house with home automation gadgets. I reached out to First Alert, and they were so kind to send me a review unit of their HomeKit enabled Onelink smoke and carbon monoxide alarm.

What is HomeKit

HomeKit is Apple’s attempt to standardize home automation and to offer users an easy way of interacting with home automation equipment, such as smoke detectors, garage door openers, lights, etc. Apple introduced HomeKit with iOS 8, but it took a while for device manufacturers to catch on and start selling products that would integrate with Apple’s platform. For a while, I thought that HomeKit would be another CarPlay – an excellent idea and technology with lacking support from manufacturers.

Review: HomeKit enabled smoke alarm from First Alert

It had taken a few years before HomeKit enabled devices became more prevalent, but the Consumer Electronics Show (CES) in 2017 made clear that HomeKit is here to stay.

Getting started with home automation

Tim Cook described how he uses HomeKit and Siri during one of the last earning calls. He would say “Good morning Siri,” lights would turn on, and his coffee maker would start brewing coffee. I didn’t want to go quite as far. I get up one to two hours before my wife does. If I said “Good morning Siri” and the lights would turn on, my wife would slap me in the face. So my goal was to introduce HomeKit in an area that has interested me since Nest launched the first “smart” smoke detector. Nest’s devices didn’t work as well as I had hoped and when Google acquired Nest, they dropped off my personal technology radar. Since then I have been waiting for someone to develop a HomeKit enabled smoke detector. First Alert came through when they released the Onelink Smoke + Carbon Monoxide Alarm.

Review: HomeKit enabled smoke alarm from First Alert
Onelink Smoke + Carbon Monoxide Alarm

The First Alert Onelink is a HomeKit enabled smoke and carbon monoxide detector. It’s available as a battery-powered or a hardwired unit. The review unit First Alert sent me was hard wired. I wanted the battery-powered unit but forgot to mention that. Fortunately, when we bought our house, it already had one pre-wired smoke detector installed that had long expired. I took it out a few years ago but left the wiring intact. As a result, I could reuse the wiring for my new HomeKit enabled smoke detector, which simplified the installation.

Feature overview

First Alert’s Onelink smoke- and carbon-monoxide alarm makes it easy to get started with home automation and Apple’s HomeKit. The Onelink smoke alarm is equipped with a photoelectric smoke sensor and an electrochemical carbon monoxide sensor.

Remember that photoelectric smoke sensors work best for detecting smoldering fires but are not as effective for detecting rapidly spreading fires. So in a perfect world, you want to have both types of smoke alarms in your home.

Review: HomeKit enabled smoke alarm from First Alert

You can interconnect the Onelink alarm with various other brands and models by using the provided adapters. That means I can add wireless Onelink units to the wired unit I just got, instead of having to add additional wires throughout the house. For a full list of compatible models, check out the FAQ on First Alert’s support page.

  • HomeKit enabled: You can ask Siri to dim the night light or check for smoke and carbon monoxide alerts.
  • Notifications: Onelink notifies you via push notifications while at home or away.
  • Control via the app: You can silence nuisance alarms or test the smoke detector directly from within the Onelink app.
  • Nightlight: The wired (120V AC) version of the One Link offers a convenient night light that you can dim but not turn off completely. The LED doubles as an indicator that the unit has power.


Thanks to my existing wiring, installing the Onelink was relatively straightforward. Before you begin, make sure to turn off power to avoid electric shock. I double-checked that there was no juice in the wires using a non-contact voltage tester. Then I connected the black and the white cables from the smoke detector with the pre-installed wires and screwed on the backplate. Since I only have one wired smoke detector, I didn’t have to connect the third (orange) cable.

Review: HomeKit enabled smoke alarm from First Alert

As soon as I had connected both cables, the led on the Onelink turned on, and for a moment, I thought I had not cut the power. Later I found out, that the Onelink smoke alarm has a built-in battery that powers it during power outages. That was the reason why the unit turned on before I switched the power back on.


To setup and configure Onelink you have to download and install the Onelink app from the App Store. An easy-to-follow wizard guides you through the initial setup. It only took me a few minutes to complete the installation.

HomeKit compatibility

When First Alert had released the Onelink smoke alarm, it didn’t fully support Apple’s Home app in iOS 10. That issue has been fixed by now through a firmware update. But some users complained about that lack of support on Amazon’s review page. In my opinion, First Alert could have provided the firmware update sooner, considering that Apple makes developer Beta versions of iOS available as early as June, during the World Wide Developer Conference (WWDC). When I installed my review unit, it notified me about the firmware update within a few minutes, so I didn’t experience any issues.

Additionally, many of the configuration options and features the Onelink detector offers are only available through the Onelink app but not through Apple’s Home app. As a result, you can see your Onelink devices in the Home app, but you cannot interact with them. First Alert writes in its FAQ that they are actively pursuing an update to the Onelink Smoke+Carbon Monoxide Alarm that achieves full functionality within the Apple Home app.

I don’t consider that gap a showstopper as long as I receive push notifications in the event of an alarm.

Siri commands

You can interact with Siri using the following commands:

  • How is my CO Detector?
  • How is my Smoke detector?
  • Do I have a smoke detector?
  • Is the smoke alarm tripped?
  • Is the CO alarm tripped?
  • How is the Carbon Monoxide detector?
  • Change the brightness on my smoke detector to [x] percent.

Room for improvement

Right now there is no easy way to test push notifications, other than by using a smoke detector test spray to trigger the alarm. I hope that First Alert improves its app so that you can test push notifications by pressing the test button on the Onelink unit.

HomeKit enabled smoke alarm from First Alert

Onelink is an easy-to-install and user-friendly smoke and carbon monoxide alarm that nicely integrates with Apple HomeKit. It offers push notifications in case it detects smoke or carbon monoxide and supports Siri commands to check for the status of the unit. The only thing missing in my opinion, are push notifications for test alarms. First Alert has helped me to get my feet wet with HomeKit. I am sure it is only the beginning of a fully automated home.

7 thoughts on “HomeKit-enabled Smoke Alarm [OneLink Review]”

  1. Your point about over-complexity is well taken. However, the alarm on the detector will sound for smoke or CO regardless of integration with external systems. The further integration in the Apple Homekit framework allows for *additional* features to be gained. I use mine to trigger all the lights on and to unlock doors and open the garage – hopefully, all of which will allow for simpler egress in the event of an actual fire or CO event.

  2. Take care not to violate one of the most important principle of design, particular when safety is paramount. KISS—Keep It Simple Stupid.

    HomeKit is fine if it adds benefits, but it shouldn’t introduce dangerous complexities. If it introduces ways these alarms could fail to alarm, it is not a good idea. You want an alarm system that makes a heck of a lot of noise when it detects smoke or carbon monoxide. Compared to that, nothing else matters.

    A brother-in-law’s pickup truck illustrates that. Modern and high-tech, it refused to run, claiming the transmission was overheating. That was bosh, since the signal came on after it had been driven only about a hundred feet, not enough to overheat anything.

    But that complexity meant he could not drive it to the shop. It had to be towed. And the fact that the problem being claimed wasn’t the real problem meant tracing down the real problem took a month, with a GM engineer having to be called in to consult.

    Needless complexity, particularly false alarms, can lead people to shut overly intrusive warning systems off to preserve their sanity. Then when that system is needed, it isn’t there.

    • Hi Michael,

      Valid point – I think Nest struggled with some of that in the beginning. First Alert, on the other hand, have been in the smoke alarm business for a while, and just added newer tech to existing and proven technology. So I am not too concerned about the reliability of their detectors.




Leave a Comment