Best Water Leak Sensors of 2021

A leaky pipe flooding your home is enough to ruin your day, your furniture, and your home maintenance budget. That's why we chose the Resideo Wi-Fi Leak & Freeze Detector as our top pick because it's a smart water sensor with Wi-Fi capabilities and an easy setup.

It senses changes in water, humidity, and temperature to protect against mold and frozen pipes. Still, it doesn't have a companion shutoff valve like some competitors, so you need to turn off the water supply during a flood manually.

Each of our picks effectively guards your home against water damage and cuts your water bill with clever alert systems and long battery lives. Read on to see how they compare and find the best for you.

If you're home when the sensor detects an issue, it's hard to ignore its alarm. At 100 dB, it's one of the loudest alarms on our list—it's louder than a blender, garbage disposal, or even a diesel truck. This is helpful for folks without a mobile device nearby when a flood begins.

We like the suite of sensors that spot significant changes in humidity, temperature, and water level. Although you'll know as soon as it detects water, it takes up to 60 seconds to spot a plumbing leak (to preserve battery life). This is slower than the other sensors on our list, which all notify you immediately, but fast enough for most small leaks.

We're big fans of the four-foot sensing cable that you can extend into tight spaces where a water leak sensor normally wouldn't fit, like behind a washing machine.

We like that the Resideo is compatible with Amazon Alexa, Google Assistant,^† and IFTTT, so you can check the sensor status on your smart speaker or have other smart devices react to a flood. The three-year battery life is a nice bonus too.

Unlike Flo by Moen, there's no companion automatic water shutoff valve for this Resideo leak detector, so turning off the water during a flood is more of a hassle. Automatic valves are a nice feature to have, but they can easily blow your budget.

Overall, we think Resideo is one of the best water leak detectors on the market, even with the slower detection speed.

This detector comes with a generous six-foot sensor cable that squeezes into narrow gaps behind your appliances. Although you can rest the leak detector on the floor without a sensor cable, it's less secure than wall-mounting the sensor and using the cable. Wall-mounting is great for homes where children might move the sensor from the laundry room to a toy bin.

When a water sensor alarm goes off, you'll get a notification on your smartphone, and the smart device will start beeping. The quiet beeps are no match for a proper siren—you may as well rely on the mobile app to tell you when there's a leak.

Unlike the Resideo sensor, Flo doesn't offer any smart home compatibility—at least if you don't want to buy the Flo by Moen Smart Water Shutoff (about $550), which costs more than 10 times as much as the water alarm sensor (yikes). With the valve, you gain access to Google Assistant and Amazon Alexa integration, but there are cheaper options for smart home and shutoff valves.

Overall, we like Flo by Moen's fast sensor speed and optional shutoff valve as an alternative to Resideo, our top pick. But its weak alarm sound and expensive smart home upgrade requirements keep it from snagging the top spot.

Despite its low price, Kangaroo manages to cram humidity and temperature sensors alongside the water-detection capabilities. Considering that the pricier D-Link and LeakSmart models don't have as many sensors, this is a win for Kangaroo. Beyond that, Kangaroo's lack of a sensor cable hampers its water leak detection abilities in cramped spaces.

There's also no audible alarm on this unit, so you need a mobile app to find out when your toilet leaks. You might consider pairing Kangaroo with a cheap water leak alarm like The Basement Watchdog for a piercing siren, but it won't save much money compared to Resideo. Kangaroo also has the shortest battery life on our list, with a meager one year compared to Resideo and Moen's three-year battery lives.

Kangaroo manages to outsmart Flo by Moen's smart home skills for a much lower price, but you need to pay for a subscription ($99 per year) to unlock Alexa and Google compatibility.

Overall, Kangaroo is a great option for folks who need basic sensing and mobile app controls. But if you expect the complete smart home and loud siren experience, we recommend sticking with Resideo.

You'll find Google Assistant and IFTTT compatibility on this D-Link spot leak detector. But there's no support for Amazon Alexa, so Resideo is ultimately a better pick for Alexa users. Still, we like that D-Link doesn't charge extra for smart home compatibilities like Kangaroo and Flo by Moen do, making it more accessible overall.

D-Link uses only a single water sensor instead of the extra humidity and temperature sensors included on other leak detectors. Still, the water leakage sensor is lightning fast, and the six-foot sensor cable's flexible installation keeps D-Link in the running against cheaper detectors like Kangaroo. The sensor also has a loud 90 dB siren that backs up the D-Link's mobile device alerts.

Overall, we like D-Link for its robust customer support and simple, effective water leak sensor. It's a great alternative to Resideo, especially if you're looking to expand your Google smart home.

Shutoff valves are hardly a unique feature, but LeakSmart is one of the more affordable options for this kind of setup. Although the list price is close to $500, it usually sells for about $250 on Amazon, so the price isn’t as bad as it seems—Flo by Moen charges over $500 for its shutoff valves. (We use list prices on SafeWise because they're more stable, but they often don't reflect actual retail pricing.)

Unlike LeakSmart's in-line valves, which require some plumbing skills, Snap quickly attaches to ball- and gate-type valves. Still, the company recommends having a professional install the valve for the best results, going as far as offering a five-year warranty instead of the one-year option on DIY installs.

This Zigbee smart valve connects to the Wi-Fi-enabled smart hub, allowing it to communicate with the leak detection system around your house. You can set these sensors to tell the valve to shut off the water flow or alert you to a problem through a text, email, or push notification.

Overall, we're fans of LeakSmart's connectivity, sensitivity, and option for a long warranty. But paying a pro for a longer warranty likely won't save you much money.

The Fibaro Flood Sensor is one of few leak detectors that support Apple HomeKit, so it's worth considering if you're deep in the Apple smart home ecosystem. Unfortunately, it doesn't connect to Wi-Fi without a HomeKit hub, so there's no remote access when you're out of Bluetooth range. It doesn't have a sensor cable, though you can attach up to 10 feet of wire for similar functionality.

The Basement Watchdog is a low-tech moisture alarm that doesn't connect to smartphones but is an incredibly affordable way to hear a loud 110 dB siren at the first sign of a leak. It doesn't detect humidity or temperature but comes with an impressive five-year warranty. We like this alarm for its low price (around $12) and flexible sensor cable. If you want a no-fuss, classic sensor to keep your home safe for a modest price, The Basement Watchdog is a great option.

For its size and simplicity, the Zircon Leak Alert is a powerful device. App-controlled devices are a nice bonus, but it's hard to beat Zircon's affordability and ease of use. Setup has two steps: add batteries and put the sensor under your sink, washing machine, or toilet. There's no sensor cable like The Basement Watchdog, but it comes in cheap multipacks to help cover every room in your home.

The HydroCheck WaterWatcher caught our attention for its unique ability to turn off water-using appliances when it detects a leak. Plug it into a standard outlet and connect the appliance you want to control, like a washing machine or dehumidifier. When there's a leak, the WaterWatcher cuts the power to the appliance to keep flooding to a minimum. It's a little pricey (about $80) for a simple sensor without a mobile app, but its controlled outlet fills a useful niche.

The Resideo Wi-Fi Water Leak & Freeze Detector is one of the best water leak sensors because it's discreet until there's trouble. We like that this smart water leak detector emits a loud alarm and sends push notifications when there's a problem. While it's not as fast at detecting leaks as the competition, its strong smart home compatibility helps make up the difference.

If you're looking for more information on preventing home flooding, check out our home flooding resources, tips for what to do when your house floods, and our sump pump reviews if you need to get water out of your house.

Our quest for the best water sensors began by digging through professional and customer reviews. We focused on smart water sensors with mobile app controls and looked at some budget options without Wi-Fi. In our search, we considered 17 different brands and narrowed our list to 9 detectors.

After assembling our list of star players, we scoured resources like owners manuals, product specs, and unboxing videos. These were all instrumental in the decision of which water leak detector reigns supreme. Learn more about our methodology for this and other guides on our site.

• What Do I Do If My House Floods?
• Common Pipe Problems and How to Avoid Them
• Buying An Older Home? Check for These 5 Things First
• How To Know If You Live in A Flood Zone
• How Can I Prevent My Home from Flooding?

1. Honeywell, "Welcome to Resideo – The New Company Name Of Our Soon-To-Spin-Off Homes Business," July 2018. Accessed August 27, 2021.