Nest Protect review: a smoke detector for the smartphone generation

Back in 2011, Nest did the impossible: It made thermostats sexy. Apple veterans Tony Fadell and Matt Rogers applied their iPod-designing expertise to the largely utilitarian world of home-climate control, creating the Learning Thermostat, an appliance aimed squarely at the gadget-obsessed citizens of the smartphone age. And then, earlier this year, Fadell and Rogers took on another traditionally banal (but utterly important) aspect of home life: the smoke detector. The conceit of the Nest Protect was to bring some of the same aesthetics and smart features that made the company's first product a success.

The result is a smoke/carbon monoxide detector with mobile device connectivity and a range of expressions that go far beyond the old beeping alarms, as well as a unique gesture feature that lets you silence the device with the wave of a hand. Admittedly bummed at the inability to test the Learning Thermostat in my prewar New York City apartment building, I happily jumped at the opportunity to review the Protect. So Nest sent along two devices, a can of something called a "smoke detector tester" and, thankfully, thorough instructions on how one goes about testing smoke detectors without accidentally burning the house down.


Given Nest's origins, it's not especially surprising that the company managed to make even the product's box a thing to behold. The message is pretty clear: If Apple ever saw fit to produce a smoke detector, it would look something like this. It's a well-designed bit of packaging that looks more suited for a Best Buy vending machine than a dusty hardware store shelf. Inside, you'll find a wall mount, a set of four screws embedded directly into the cardboard packaging and an awful lot of paperwork -- after all, making sure the device works properly could be a matter of life or death. As for the Protect itself, you've got two options, both at the same price point: a battery-operated model, and a wired version for those who want to tap into their home circuitry. Seeing as how I won't be using the detector permanently, I opted for the former, which comes with six AA Energizer Lithiums pre-installed.

Like most current smartphones, the Protect comes in either black or white. Nest sent me two white devices, thankfully -- far better for blending in on my apartment walls. Perhaps some of you willing to drop $99 on this sort of product want to make the thing as conspicuous as possible, but personally, I'd prefer not to have to discuss my smoke detector with everyone who visits my apartment (that's what record collections, bookshelves and stuffed grizzlies are for). With that in mind, it's not surprising that the Protect has a much subtler aesthetic than the company's first device, though it's still unquestionably a much nicer object than the vast majority of smoke detectors I've encountered.

The Apple connection is pretty clear here, right out of the box. With the clean lines and rounded corners, a quick look at the Protect's profile invites comparisons to a flattened Mac mini or Apple TV. The front of the device, meanwhile, is almost all grille -- this is, after all, a product designed to wake you from deep sleep a couple of rooms away. A big, circular button sporting a Nest logo sits in the middle of the dotted plastic face. Mobile devices aside, this button will be your primary method for interacting with the Protect. You'll press it several times during setup, any time you want to test the detector and when you want to quiet the alarm.

There's a thin circle in the button, with faint, light gray text so befuddled houseguests know they're looking at a smoke and carbon monoxide detector. In this spot, you'll also see the light that emanates from behind the button, forming a glowing ring in the center of the smoke detector. This is how the Protect manages to communicate without always making noise. Nest opted not to include a display, likely because you won't find yourself physically interacting with a smoke detector nearly as often as a thermostat. The vast majority of the time, there's no light on at all, allowing it to blend in with its surroundings and conserve battery life.

Still, the light is pretty expressive. During the setup process and testing, it turns blue, letting you know it's working and connected. When you turn off the lights at night, it glows green for a moment to let you know everything is all right with the sensors and batteries (if there's an issue, it'll turn yellow and tell you what the matter is when you wave your hand in front of it). And if you so choose during the setup process, the pathlight will light up when it detects motion in the dark, a sort of beacon to help you navigate your way through a pitch-black room. The light turns yellow as an early warning sign of a problem and red when it's time to sound the alarm.

On the back of the Protect, you'll find detailed explanations about each of the light colors and the standard warnings that come with a product like this. There's a micro-USB port in the middle for "internal use only," according to Nest, and holes for attaching it to the wall dock, a process that just requires a simple twist. At the bottom are two screws you'll need to take out to remove the back while changing the batteries. When you first take the Protect out of the box, you'll also spot a light blue tag popping out the back -- this ensures that the batteries aren't in before you're ready for them. You'll need to yank that out to get started.


Pull out the tab and press the button and the Protect will say, "Hi." The smoke detector has a soft-spoken, feminine voice, the sort of strangely calming robotic presence you'd like guiding you in a time of emergency. The voice follows the greeting by asking you to choose whether you'd like her to speak in Spanish or English. Next up, you'll be prompted to test the Protect, to make sure things are all right. "The alarm will sound," she explains. "The alarm is loud." She ain't lying. It's grating, ear-piercing and strikingly loud, and you'll hear a total of six beeps as the Protect checks the smoke and then carbon monoxide sensors. It's annoying when you're testing the thing, sure, but when it comes to smoke alarms, loud is good. "The test is finished," she adds, calm as ever. And, if all goes according to plan, "everything is okay."

Now it's time to download the app. Ahead of Protect's release, the company issued an app that monitors both its thermostats and smoke detectors, available for iOS and Android. Create an account through Nest's site (if you don't already have one); use your handset to scan the QR code on the Protect's back (or manually enter a key, if you're so inclined); and the app will take you through a simple process of connecting it to your wireless network. If you've ever connected anything like a Chromecast to your home WiFi, this should be a familiar process, though I did have to repeat it a few times as everything attempted to connect. I spoke to a Nest rep, and the company's not sure what happened there, but the problem resolved itself before I had to pull my hair out. When you're done, the voice will tell you that she's "connected to the internet" and everything's ready to go. If you've got a second Protect, you'll be prompted to connect that, as well. It's a similar process, albeit slightly shorter with some redundant steps removed.

Next, it's time to take the old smoke detector off the wall -- though the company suggested I not actually do that in my testing, as the review units weren't quite final. This part of the process is naturally a bit more involved, should you opt for the wired version. According to the included instructions, the ceiling is the best place your Protect -- or, failing that, high up on a wall. In either case, it's best to avoid obscuring any edge of the detector with a tight corner. Once you've found the right spot, screw the backplate into the wall and snap the Protect in place.


And now the fun(?) part. If the beeping during setup didn't set off the neighbors, I assumed the testing would. No one came knocking, however, which should give you some idea of how much you can count on the people in your building in case of emergency. Good thing I have four smoke detectors in my apartment at the moment. Nest equipped me with the Smoke Sabre, a smoke-detector tester in an aerosol can. With a spritz (or with actual smoke or carbon monoxide, naturally), the ring of light will turn yellow, alerting you that something is up. The Protect gives you a window of a few seconds in yellow, dimming slightly when it spots you, letting you know that you're in the sweet spot and can reset the alarm with a tap of the center button wave -- just as you might wave away the smoke when overcooking something on the stove. The idea is to stop false alarms before they start -- so if you're in the kitchen and something starts smoking, you don't have to deal with emergency alerts during a non-emergency.

I had a bit of trouble getting the gesture-based override to work during the trial, in spite of some frantic waving. I contacted Nest about the issue, and a rep told me that, due to federal regulations, there are two versions of the alarm. The less serious of the two can be overridden by the user. The other just goes straight to alarm. Apparently I've been hitting the old Smoke Sabre a little too hard. The upside, however, is that I got to see the Nest spring into action (the downside, naturally, is that I got to hear it, too). This, it turns out, is why you installed that app -- like the smoke detector itself, it will sit around idly for the majority of the time, a subtle reminder that everything is copacetic.

When the Protect encounters an issue, however, you'll get a push notification on your mobile device (an optional, but highly recommended feature). The normally green ring in the center of the app will turn red, along with a quick indicator of what's wrong (in this case: "Smoke"). Tap on that and you'll get a breakdown of your alarms' statuses -- e.g., "Smoke" for the dining room and "All Clear" for the kitchen. Tap through to notes and the app gives you a full breakdown of what happened -- at 4:47 PM: "There is smoke. The alarm is sounding." I was eventually able to hush the sound by hitting the button, and the timeline mentions that as well. At the top of the page is a "What to Do" note, including the usual stop, drop and roll instructions (which you hopefully don't need to pick up a smartphone to remember). There's also a big red button at the bottom for dialing 911.

Wrap up

I'll admit it's been a while since I've been in the market for a smoke detector. A cursory scan of Amazon, however, indicates an average price between $10 and $30, with combo smoke/carbon monoxide detectors landing at the higher end of that spectrum. In either case, it's a range the $99 Protect misses by a country mile. Of course, this isn't just any smoke detector. Like the Learning Thermostat before it, it's a bit of home electronics aimed at gadget nerds, and certainly Nest has managed to do a lot in an otherwise staid category.

It's a lovely object, so far as these things go, and its expressive center lighting and voice directions offer a lot more than the standard series of beeps: alerting you to emergencies, low batteries and even lighting your way at night. The button-based hush can save your eardrums and the smartphone alerts may well save some lives. For most, however, standard smoke detectors will likely still do the trick. Even though certain device idiosyncrasies can be a hassle, $99 still feels like a lot to pay, given the industry average. And for those living in larger homes, it's a price that'll add up fast.

Update: At the time of this review the Nest Protect featured the Nest Wave gesture-based controls, allowing the user to turn off the alarm with a wave. On April 3rd, 2014, Nest announced a voluntary recall of all Protect units after the company found that it was possible to accidentally activate the Nest Wave feature, causing the detector to delay reporting a fire. In light of this, we withdrew our Engadget Score and recommendation until the problem was resolved. Nest resumed selling Protect devices on June 16, 2014, with the gesture-based controls shut off as default. Existing Nest Protect users should have received an over-the-air software update to their devices disabling the Nest Wave feature. In light of this and the a new lower price of $99, we have revised this review and reissued the Engadget Score.