Your Apple Home Is Missing Its Most Important Sensor

A HomeKit-compatible smoke detector sends a critical alert to your iPhone, lights up every room in the house through a single Apple Home automation, and unlocks your smart locks to clear the exit path — all before you even smell smoke. That combination of instant notification and whole-home response is what makes a smart smoke detector worth the price over a twenty-dollar hardware store unit.

The catch is that finding one in the United States just got significantly harder. First Alert, the brand behind the only two widely available HomeKit smoke and carbon monoxide alarms sold in America, discontinued both the Onelink DC10-500 and the Onelink Safe & Sound in 2025. Neither has a HomeKit-compatible replacement. If your Apple Home covers lights, locks, cameras, and a doorbell but skips fire safety, you are not alone — and the options for fixing that gap are thinner than most people expect.

What HomeKit Actually Does With a Smoke Sensor

Apple’s HomeKit Accessory Protocol defines two relevant sensor services. The smoke sensor service exposes a binary SmokeDetected characteristic — either smoke is present or it isn’t. The carbon monoxide sensor service adds CarbonMonoxideDetected and, optionally, real-time CarbonMonoxideLevel readings in parts per million along with a CarbonMonoxidePeakLevel record. Both services also expose battery status, tamper detection, and fault indicators.

What this means in practice: when a HomeKit smoke detector trips, the Apple Home app can trigger any automation you have set up. Lights on, locks open, HomePod announcement, camera recording — all simultaneous, all automatic. The notification arrives on every iPhone and Apple Watch linked to the home, and it does, though, come with a caveat. Remote notifications, automations, and the multi-device alerts all require a home hub. That means a HomePod, HomePod mini, or Apple TV 4K running at your house. Without one, the physical alarm still sounds, but the smart features vanish the moment you leave your own Wi-Fi network.

If you already have a hub configured, it is worth verifying it is up to date and assigned as your primary hub. Our guide to checking your Apple Home hub settings walks through exactly where to find that buried status screen. And if you are still in the early stages of building an Apple Home setup from scratch, getting the hub right first makes every accessory you add afterward more reliable.

The One US Option That Actually Exists

The Owl Wired Combined Smoke, Carbon Monoxide, Motion & Climate Sensor is, as of March 2026, the only currently manufactured HomeKit smoke and CO detector you can buy new in the United States with full UL-268 certification. It costs around $170, hardwires into an existing smoke detector circuit with battery backup, and connects over 2.4 GHz Wi-Fi plus Bluetooth 4.2.

The sensor coverage is genuinely impressive. Photoelectric smoke detection, electrochemical carbon monoxide sensing, passive infrared motion, temperature, humidity, and ambient noise level — all packed into a single ceiling mount. It also interconnects with other hardwired smoke detectors in the home using a third wire, which means if the Owl trips, your existing dumb detectors sound off too. That interconnection detail matters more than any smart feature for actual fire safety.

I do want to flag something practical. Some buyers have reported delivery delays and occasional hardware defects through third-party review sites. The product ships directly from Owl’s own store at getowlhome.com, not through Amazon or Apple. That means returns and support go through Owl directly. It is not a dealbreaker, but it is the kind of friction you should know about before committing $170 to a ceiling-mounted device you cannot easily test before installation.

What About Everything Else?

The short answer is that every other HomeKit smoke detector either left the US market, never entered it, or requires a hub from a different ecosystem.

Netatmo makes a solid Smart Smoke Alarm with a 10-year sealed battery and native HomeKit support. It detects smoke only — no carbon monoxide — and it is available on Apple.com in the UK and across Europe. Netatmo announced US availability back in 2018 and never followed through. Their separate Smart Carbon Monoxide Alarm is equally region-locked.

Eve Smoke, a Bluetooth-only smoke and heat detector that works exclusively with Apple HomeKit, is certified to European standards and explicitly will not be sold in the US, Canada, or Mexico. The Aqara Smoke Detector runs on Zigbee, requires an Aqara hub, reaches HomeKit through Matter over Bridge, and is likewise Europe-only. Sensereo’s MS-1 deserves a mention for being the first Matter over Thread smoke detector — it works with HomePod mini or Apple TV 4K as a Thread Border Router — but it carries only EU and UK certification. Using it in the US could affect your home insurance.

For readers outside the United States, the landscape is meaningfully better. Netatmo, Eve, Aqara, and Sensereo all sell into European markets, and Thread-based options like the Sensereo MSC-1 (a combined smoke and CO unit on pre-order at $70) signal that the technology is moving forward even if the US regulatory pipeline has not caught up.

The Free Workaround Already on Your Shelf

Here is the part I find genuinely clever. HomePod and HomePod mini have a feature called Sound Recognition that listens for the specific acoustic signature of a smoke or carbon monoxide alarm. Not a HomeKit alarm — any alarm. The twenty-dollar detector from the hardware store, the decade-old unit hardwired into your hallway ceiling, the detector in the kitchen that goes off every time you overcook toast. If it sounds, and your HomePod hears it, you get a critical alert notification on your iPhone and Apple Watch that cuts through Do Not Disturb and Silent mode.

All of the audio processing happens on-device. No recordings leave the HomePod, no data goes to Apple, and the feature works over the local network without an internet connection. The one requirement is that the HomePod needs to be close enough to physically hear the alarm. In a small apartment, a single HomePod mini covers the whole space. In a larger home, you might need one per floor — which is not a bad reason to pick up a second HomePod mini if you have been looking for an excuse.

To enable it, open the Home app, tap the HomePod, scroll to Accessibility, and flip on Sound Recognition. Then toggle both Smoke Alarm and Carbon Monoxide Alarm underneath it. The setting is buried in a place you would never stumble across unless someone told you it was there.

Automations Worth Building

Whether you go with the Owl Wired or rely on HomePod Sound Recognition, the automation layer is where Apple Home earns its value. A smoke detection trigger can activate a scene that turns on every light in the house at full brightness, unlocks HomeKit-compatible smart locks — which is especially relevant if you have already set up locks through a guide like our HomeKit smart lock roundup — and begins recording on all HomeKit Secure Video cameras.

The practical thinking here matters. In the worst case of a fire at 3 AM, you want every hallway lit, every door unlocked, and a recording that shows your insurance company exactly when the alarm triggered and what happened. That sequence runs in seconds through a single Apple Home automation.

One edge case to plan for: if your internet goes down, a Wi-Fi-connected detector like the Owl Wired loses its remote notification path. The home hub needs local network access to fire automations. The physical alarm still sounds — that never depends on your network — but the smart layer is only as reliable as your home’s power and connectivity. A UPS on your router and home hub is cheap insurance for exactly this scenario.

Building Code Reality Check

I want to be direct about something that gets glossed over in most smart home guides. A HomeKit smoke detector is not automatically compliant with your local building code. Fire safety requirements vary by state, county, and even city, and many jurisdictions mandate specific wiring configurations, interconnection standards, or listing certifications that some smart detectors do not carry. The Owl Wired’s UL-268 listing and hardwired interconnection make it the closest to universal code compliance among HomeKit options, but “closest” is not “guaranteed.”

Before replacing any existing detector or relying on a smart detector as your only fire safety device, check with your local fire marshal or building inspector. And if you rent, your landlord’s insurance may have its own requirements. A smart smoke detector should complement your code-required setup, not replace it without verification.