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Our runner-up pick, the D-Link DCH-S161, has been discontinued. We’ve removed it from this guide and are in the process of testing new models.
Splashing the day away sounds like fun—unless the splashing is happening in your basement or kitchen, or there’s a puddle seeping from the toilet. A smart water-leak sensor can lessen the impact of plumbing problems by alerting you the moment they’re detected, whether you’re at home or away. We recommend the Flo by Moen Smart Water Detector because it’s the only device we tested that responded quickly to both water and connectivity issues. It’s wire-free, making it easy to place, and it includes temperature sensors, so you can detect when pipes are beginning to freeze, before they burst.
The Flo monitors for water and temperature changes, even in hard-to-reach places, thanks to the included extender cable. It also responds quickly to emergencies, sending smartphone notifications, emails, and texts.
The Flo by Moen Smart Water Detector responded consistently both to leaks and to connectivity or power issues, and it did so faster than most of the devices we tested. It’s also cordless, so it’s easy to place without having to worry about an electrical outlet. The Flo’s main unit is droplet-shaped and has sensing probes on the bottom of the device; you can also attach a 4-foot extender probe, so you can sneak it into tight spaces. We like that the Flo also measures temperature and humidity and has an onboard audible alarm (although it isn’t very loud). Unfortunately, it doesn’t integrate with popular smart-home platforms, like Amazon Alexa, Apple HomeKit, and Google Assistant, but it does work with Flo’s water shutoff system—a smart water valve that can turn off your home’s water service if it detects a potentially catastrophic leak
The Proteus Aquo is more customizable than any other water-leak sensor we tested. However, there’s no dedicated app, it needs to be plugged in, and it’s twice the price of our top pick.
Compatible with: Amazon Alexa, IFTTT
The Proteus Aquo Wi-Fi Water Sensor is more customizable than any other standalone device we reviewed. You can program alarm times, schedule power notifications, and integrate it with Amazon Alexa and IFTTT. This device also has the loudest audible alarm (85 dB) of any system we tested, and it is the only one that can integrate up to five sensors simultaneously (including one for a sump pump). But that customization can be complicated, there’s no dedicated smartphone app (you use a Web browser to administer it), the device needs to be plugged into the wall, and it’s twice the price of our top pick.
The Flo monitors for water and temperature changes, even in hard-to-reach places, thanks to the included extender cable. It also responds quickly to emergencies, sending smartphone notifications, emails, and texts.
The Proteus Aquo is more customizable than any other water-leak sensor we tested. However, there’s no dedicated app, it needs to be plugged in, and it’s twice the price of our top pick.
I first started testing smart-home items back when the only smart-home items were X10. Over the past 15 years, I’ve had my hands on everything from remotes and security cameras to AV receivers and smart light switches. I’ve also written tech articles for The New York Times (Wirecutter’s parent company), Wired, Men’s Health, and others.
According to the Insurance Information Institute, water damage was the second most common cause of claims from 2014 to 2018, and the third most expensive. Unwanted water can come from any number of sources: old roofs, leaky water heaters, malfunctioning sump pumps, old toilet valves, decrepit fish tanks, and cranky washing machines. The damage it wreaks can be equally varied: Water can warp floors, stain furniture, ruin old photos, and breed mold. And the aftermath of a leak can be expensive: According to Home Advisor, cleanup costs can be anywhere from $3.75 to $7 per square foot, depending on the type and volume of damage, as well as on your location.
Smart water-leak sensors are for anyone who is worried about small leaks turning into big ones, and anyone who doesn’t want to wait until they step into a flooded room to find out. There are plenty of non-smart water-leak sensors that trigger a siren when water is detected, but they may go unheard if they’re in a bathroom or deep in the basement, or if you’re not home. A “smart” water-leak sensor, however, sends alerts right to your smartphone no matter where you are. Most water-leak sensors are tiny pucks or sensor points that you can place near or underneath a water source. Some use battery power, and others need an outlet. When a leak happens and water makes contact with the sensors in one of these devices, it will send you a smartphone alert, email, and/or text (and, in some cases, sound an audible alarm).
Water-leak sensors are not foolproof. They do need to be placed thoughtfully, so they are in the path of where water might flow. Some have cords that allow you to better reach leaky places. Ideally, you want to place multiple sensors throughout your home to cover a variety of places where water leaks might happen.
They also are only an alarm system—on their own they don’t protect your home from damage. There are devices that can automatically turn off your water line when a leak is detected, but those systems typically cost hundreds of dollars and may require a visit from a professional installer or plumber, adding even more to their cost; the devices in this guide let you monitor for leaks and then take action yourself.
We looked for do-it-yourself devices that can alert you to even small leaks so you can fix them before they become big problems. After combing through as many roundups and reviews as we could find, we’ve come to the conclusion that there is no one perfect smart water-leak sensor. However, we considered ones that included most of the following:
The average price of a smart water-leak sensor is around $50. Though some people may question the value, the cost to replace furniture, rugs, and memories is much higher. (You can get a leak sensor that will set off an eardrum-piercing tone for as little as $10, but if you want smartphone alerts and remote access, be prepared to pay a bit more.)
We set up each device according to its instructions, downloaded the necessary apps, and connected each device directly to a Wi-Fi network or a smart-home hub, when needed. For each of our tests, we used apps on an iPhone SE, an iPad, a Samsung Galaxy J7 running Android Oreo, and a Nokia 3.1 running Android 9 Pie, when possible.
Not every water leak results in a flooded basement, so we doused each smart water-leak sensor with four different amounts of water to see if it would react—and how quickly. Specifically, we measured sensitivity using a spray bottle, a dropper with ¼ teaspoon of water, a full teaspoon, and a ⅛ cup measuring cup. Those tests were completed about 18 feet from our router. We also tested each device from the farthest point inside our house, about 35 feet away. With the exception of a few models, most smart water-leak sensors cannot be completely submerged—although it’s possible for some to dry out and be fine, we did have one model that completely died on us. (Most manufacturers put a warning on the packaging or in the manual.)
We also timed how fast each sensor was in alerting us, both through an audible alarm (when available) and via push notification, text, or email. When possible, we integrated water-leak sensors with Amazon Alexa, Google Assistant, and Apple HomeKit, and set up triggers using IFTTT. This allows you to add an extra alert option. For instance, we set up a trigger that would turn on a smart light bulb in the living room whenever water was detected.
Wirecutter takes security and privacy issues seriously and investigates as much as possible how the companies we recommend deal with customer data. As part of our vetting process, we looked at all of the security and data privacy practices behind our product picks. We also reached out to all the companies that produce our top picks and had them answer an extensive questionnaire to confirm information that we think should be of primary concern for any potential buyer. Here are the results.
Wirecutter long-term tests all of its picks, including keeping track of hardware and software incidents. Should any privacy or security issues be found with any of our selected products, we’ll report it here and, if needed, update or alter our recommendations.
The Flo monitors for water and temperature changes, even in hard-to-reach places, thanks to the included extender cable. It also responds quickly to emergencies, sending smartphone notifications, emails, and texts.
The Flo by Moen Smart Water Detector is the only cordless water-leak sensor we tested that delivered quick alerts about water, temperature, humidity, and Wi-Fi connectivity. Powered by a replaceable button battery (CR123A), the Flo smart detector is easy to mount to a wall or to place under washing machines, refrigerators, or anywhere else. The main detector has sensor probes on the bottom, with more at the tip of an optional, included cable that can extend that reach up to 4 feet. It also has an audible alarm and the option to connect to the larger Flo by Moen Smart Water Shutoff system.
The Flo has two ways of detecting water. There are three metal probes located on the bottom of the main detector, which is shaped like a water drop. It also comes with an optional 4-foot cable with a sensor disc at the tip. Unlike with some of the other devices on our list, you can’t use both sets of sensors simultaneously; the cable plugs into a wall mount, which can keep the main detector from being submerged but prevents it from detecting water.
We ran tests using the probes on the actual detector as well as the tip of the extender cable. On average, the device’s audible alarm and tiny red LED were triggered within 1 second, with smartphone alerts clocking in regularly at the 6-second mark. We also repeatedly removed the battery and found the app would consistently send a disconnection alert within an hour. The only other device that delivered disconnection notices quicker was our upgrade pick, the Proteus Aquo, which requires an outlet and is twice the price.
The Flo’s audible alarm beeps for 10 seconds every 13 seconds. It can be silenced in the app, which also gives you the option to block alerts for the next 5 minutes or 30 minutes after the initial alarm. Our previous picks didn’t offer the option to silence alarms in the app, so this is a welcome addition. After all, having a basement filled with water is enough of a headache; having to walk through it to silence beeping is a whole other level of nightmare.
Although an app that monitors for water leaks is probably the one you hope you’ll never have to use regularly on your phone, it’s worth noting that the Flo by Moen app for iOS and Android devices is easy to use and visually pleasing, and it has a few interesting extras. Besides an Activity Log, the app displays humidity and room temperature measurements, as well as averages on those stats for the previous 24 hours and seven days. There’s also a clear battery reading (versus ones that just tell you it’s all “good”), as well as Device Settings, where you can set custom alerts for humidity, room temperature, and battery levels. All three of those can also be configured to send push notifications, emails, and/or text messages, but not to trigger other smart-home devices (see Flaws but not dealbreakers, below).
The Flo by Moen Smart Water Detector is unable to integrate with any smart-home platforms. This is slightly disappointing, since we find a lot of value in being able to link devices—for instance, you might configure smart bulbs to turn red if a leak detector is triggered. The Flo can be partnered with the Flo by Moen Smart Water Shutoff, a $400 whole-house setup that supports Amazon Alexa, Google Assistant, IFTTT, and Control4 systems.
Because it was designed to work with that whole-house system, the Flo asks for a little more information during setup than other standalone sensors do. In addition to the usual email and password, be prepared to provide your actual name, address, and phone number—this is made all the worse because the company doesn’t offer two-factor authentication, a more-secure system for logging into the app.
Although the Flo does have an audible alarm, the volume on it is just 60 dB, according to our measurements, which is substantially lower than on our other two picks. Since many of these sensors will be placed in basements and other out-of-the-way places, we didn’t consider it to be a dealbreaker. However, if you feel you need to have an audible alarm, check out one of our other picks.
The Proteus Aquo is more customizable than any other water-leak sensor we tested. However, there’s no dedicated app, it needs to be plugged in, and it’s twice the price of our top pick.
The Proteus Aquo Wi-Fi Water Sensor is unlike any other water-leak sensor we’ve ever reviewed. It delivers lightning-fast response times and customizable alert times so you can set the audible siren to go off after 20 minutes or trigger a disconnection notice after 10 minutes. It also provides the option to notify multiple phones and email addresses in an emergency—and can send phone call alerts (for a fee). Proteus also sells a splitter, so you can attach five sensor cables to simultaneously monitor multiple spots in the same immediate area. The Proteus Aquo does need to be plugged into a wall outlet, which may be an issue for some homes, and it doesn’t have a dedicated app, which is inconvenient. Also, we found support for Amazon Alexa and IFTTT to be complicated. And not least, the Proteus is twice the price of our top pick.
So why do we like it? Throughout testing, the Proteus Aquo sensor gave us some of the best response times, firing off audible alerts within 2 seconds and text messages within 4 seconds. That siren was the loudest of the lot we tested, measuring 85 dB with our decibel meter. Since the device doesn’t have a dedicated app (more on that below), it doesn’t send smartphone notifications. But you can designate as many phone numbers (for texts) and email addresses that can fit into 400 characters.
Those contacts, alerts, and all other settings are managed using Proteus Sensor Cloud, a portal you access using a web browser. Owners can opt to disable the siren or set it for a specific amount of time, as well as designate how often you want the system to keep sending alerts and whether you want notifications once water has cleared. We found the Proteus Aquo provided the best response to connectivity issues—either losing power or the Wi-Fi signal—with alerts that can be customized to trigger in as few as 10 minutes after a problem is detected.
The Aquo looks a little like a miniature spy camera. The water sensor itself is on the end of a 6-foot cable, which can be left on its own or mounted to the floor or wall via the screw holes on either side of the metal contacts. Proteus also sells a splitter ($6), so you can connect up to five sensors at once, including one to monitor a sump pump. Curiously, however, the system can’t distinguish between sensors and so will just send one general alert if water is detected.
Proteus supports Amazon Alexa and IFTTT integration, but it’s a bit more complicated than with most smart-home devices. First, this integration is available only to owners who enable the Advanced mode. After the 14-day free trial, users will need to enter a credit card, but will be charged only for services like on-demand voice alerts (9 cents per call) and extended alarm and data logging (5 cents per hour). Alexa integration is free, but is available only through the Notify Me skill. That means you will receive notifications about leaks only on your Echo devices, but won’t be able to create smart-home integrations with other smart devices. You can do that if you are handy with IFTTT, but it’s not your typical two or three clicks. Instead, we found setup to be a lengthy procedure (PDF) involving Webhooks, and the Aquo can support only one command for an alarm and one for an alarm reset. Proteus does deliver step-by-step instructions for all of this, and eventually we were able to trigger Lutron and Wyze lights to go on and off whenever the Aquo was triggered.
Besides complicated integration, it’s worth noting that unlike every other leak sensor we’ve tested, the Aquo doesn’t have a dedicated smartphone app. The company provides a way to “fake” an app by bookmarking the web page to your phone’s desktop, but it’s not a fluid experience.
We’ve started testing the Monoprice Smart Water Leak/Flood Sensor, which seems very similar to our top pick, but doesn’t support temperature alerts. We’re also looking at the Eve Water Guard, a new Thread-enabled version of the previous sensor. And Sencentric's SimpleSENCE Capteur Water Leak and Freeze Detector, a new sensor that includes a 3-foot cable that can sense moisture all along the length and can be expanded up to 15 feet with interconnecting extenders.
D-Link replaced our previous runner-up with the DCH-S1621KT Whole Home Smart Wi-Fi Water Leak Sensor Kit, which includes a plug-in Wi-Fi base that can accommodate a sensor cable or up to 16 battery-powered remote sensors that connect up to 300 feet away via the subGHz wireless band.
At 3.5-by-1.12 inches, the Phyn Smart Water Sensor is too big to slide under appliances, which means you'll probably want to add the optional Extension Node ($10) or the Sensor Cable ($26). With and without the add-ons, this sensor reacts to water quickly, however, in our testing it took about 24 hours to send an alert about power and connectivity issues, which may be problematic. It also doesn't support any smart-home integration, the on-board siren produces a relatively soft 67 dB, and it can only be silenced by pushing a button on the actual device, which may be difficult for some owners depending where it’s placed.
The Orbit B-hyve Smart Flood Sensor uses a plug-in Wi-Fi hub, which you can only get by purchasing sensors in a multipack of three, eight or 20. We think that’s a substantial upfront investment for a system that doesn't offer any smart-home integration and has an on-board alarm that measured a measly 46 dB—or somewhere between a library and a "quiet suburb," according to IAC Acoustics. The sensors do react quickly and are small enough to place anywhere (as long as it’s within Bluetooth range of the hub), but you'd better be able to reach them, since they can only be silenced by squeezing them.
The Resideo Water Leak Detector (previously known as Honeywell) was a little slower to respond to water and connectivity issues than our picks. It does have a loud (83 dB) audible alarm and dual sensors (one on the device and one at the end of the included 4-foot cable).
The Kangaroo Water + Climate Sensor doesn't have an audible alarm, and both Amazon Alexa and Google Assistant integration is a paid perk, which costs $10 per month or $99 per year. This device did respond quickly to our tests, sending smartphone notifications both when water was present within 11 seconds and disconnection notices within 24 hours. However, water notifications can be silenced only by first drying off the device, which may be tricky if it’s sitting under a washing machine.
The Govee Water Detector is a cheap model that supports Alexa integration and has a loud (97 dB) on-board siren. It uses a plug-in Wi-Fi hub, which is packaged with one sensor for $24 and sold individually for $12 each. However, it can only be silenced directly on the device, and both the hub and the sensors don't send any sort of disconnection notice when they lose the connection and/or power. In fact, when disconnected, the app showed both still connected, with sensors continuing to show full battery life even after 48 hours.
Our previous runner-up, the Fibaro Flood Sensor Z-Wave Plus, didn’t send us any type of disconnection notices. We also don’t love that it uses the SmartThings app, which is very basic and doesn’t provide a shut-off option for the alarm. The Fibaro Flood Sensor HomeKit model is almost identical, except that it uses Bluetooth, which means it didn’t respond as quickly at a distance. Also, if you want alerts when you’re out of the house, you’ll need a HomeKit gateway at home, such as an Apple TV, HomePod, or iPad.
The SimpleSence WiFi Leak and Freeze Detector didn’t have as fast a response time as other sensors on our list, and it doesn’t work with third-party devices or platforms, such as Amazon Alexa or Google Assistant. Also, this model seems to have a painfully short range compared with that of other water-leak sensors we tested, which could limit placement (unless you invest in a Wi-Fi extender). We also had a few connection problems during testing, and the app’s Wi-Fi signal-strength meter regularly displayed one measly bar when we placed the device just 25 feet from the router.
We found HomeSeer’s HS-LS100+ Z-Wave Plus Leak Sensor to be too complicated to bother with. To pair it with your SmartThings Hub, you need to use the SmartThings app, log in to your SmartThings account, and then add the code that HomeSeer provides, known as a “device handler.”
The LeakSmart Sensor is typically available as part of the LeakSmart Complete Home Water Protection System, currently a $300 package that includes LeakSmart’s hub and a shut-off valve (you can also pair it with a SmartThings Hub or Wink Hub). In our tests, the alert time wasn’t as quick as that of our top picks.
The Grohe Sense Leak Sensor is bulky and it rattles. It’s also hard to open, and the three AAA batteries fell out of position more than once during our time with it. It has an extension probe, which makes it easier to place but adds another $20-plus to the cost. It doesn’t currently support any smart-home integration, but it does have a temperature/humidity alarm—which in our testing triggered one false alert. This device also lacks real-time stats, with only a 24-hour average listed in the app.
We had two separate battery incidents with the Roost Smart Water Leak and Freeze Detector. On one occasion, it sent some strange readings that Roost support told us were due to a dead battery (even though the app said it was fine). And after we installed brand-new batteries, we received a low-battery notification from the app 10 days later. These oddities make us question the device’s long-term reliability.
Jared Newman, Best water leak detectors for smart homes, TechHive, February 10, 2020
Mike Prospero, Best Water Leak Detectors in 2020, Tom’s Guide, April 8, 2020
Darwin, The Best of the Z-Wave Water Leak & Flood Sensors, DarwinsDen.com, March 7, 2018
Rachel Cericola is a senior staff writer at Wirecutter who has been covering smart-home technology since the days of X10. Her work has appeared in The New York Times, Wired, Men’s Health, USA Today, and others. She hopes her neighbors read this bio because it would explain why she always has four video doorbells running simultaneously outside her home.
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