The 10 Best Water Leak Sensors

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This wiki has been updated 30 times since it was first published in October of 2015. Save yourself the cost and inconvenience of flood damage with one of these water leak detectors. Some of our selections for this category can even connect multiple units to the same app, so you can keep a separate sensor next to your washing machine, dishwasher, sump pump and anywhere else you think is at risk. There are also standalone units with audible alarms, in case Wi-Fi isn't an option. When users buy our independently chosen editorial picks, we may earn commissions to help fund the Wiki.

1. Guardian Leak Prevention Starter Kit

2. LeakSmart Intelligent

3. Flume 2

Editor's Notes

May 02, 2021:

There isn’t too much of a notable difference in price between smart water leak sensors and those without smart features nowadays, and by that logic, along with the added benefit of convenience that smart models offer, I’ve replaced some of our older models with smart options like the Moen Flo 920-004, Flume 2 and Guardian Leak Prevention Starter Kit - the word ‘smart’ here meaning that they can connect to other devices wirelessly, meaning that they are operable remotely, typically via a smartphone app, but not in all cases. There are still some older options I’ve left in however that don’t have wireless capabilities, like the Instapark IN07A, and Samsung GP-U999SJVLCAA, but that simplicity can add a certain convenience for some users. The Instapark is also very reasonably priced. You may also notice that most of the options I’ve added, like the LeakSmart Intelligent, Guardian Leak Prevention Starter Kit and Flume 2 are sensors with automatic shutoff valves, and, though they are a little pricier, in my opinion, they are far better for going beyond offering just leak detection capabilities - the 4th option that I included, the Moen also sells an automatic shutoff valve that can be paired with the Moen Flo 920-004. Obviously, the workaround would be to buy a smart valve and water sensor separately.

March 13, 2020:

During this round of updates, in order to make room for some of the exciting new offerings that have popped up in this category following the rise of Wi-Fi and smart-home systems, we eliminated the Prevalert P312L, Honeywell RWD21 and Ideal Security SK616. We also removed the Sump Alarm In/Outdoor, feeling that it missed the mark a bit, as far as offering users the utility they’re looking for from this category. At the end of the day, the bigger half of these rankings ended up being made up of new offerings including the Samsung GP-U999SJVLCAA, which needs to be used as part of Samsung’s SmartThings series; the Fibaro FGBHFS-001, which is geared toward Apple users; the SimpleSENCE Freeze Detector, which still offers app connectivity in spite of not needing a hub; and the; iHome iSB02, which works fine as a standalone unit, but still presents the option of being able to connect with other iHome smart devices.

A few things to keep an eye out for in this category:

Alarm: Even if you're considering a sensor with app connectivity, and especially if you’re considering one without, you’re ideally (in most circumstances) going to want a sensor with an audible alarm that you can hear throughout your house. While options like the First Alert WA100-3, which features an 85-decibel alarm, appear to be on the quieter end of things for this category, the Instapark IN07A represents the louder end of that spectrum, boasting a 130-decibel alarm. The Samsung GP-U999SJVLCAA and Zircon Leak Alert are also equipped with flashing lights for visual alerts.

Connectivity: We already got into this a bit during the introduction to this editor’s note, but for the sake of clearing things up: if you’re considering investing in a sensor with app connectivity, make sure it’s compatible with your home.

Firstly, this means making sure the sensor in question jives with your Wi-Fi network. Most of these sensors are designed to run on 2.4-gigahertz systems and many are not yet compatible with five-gigahertz systems, so keep an eye out for that.

Secondly, certain offerings are only compatible with specific smart-home systems, like Apple HomeKit’s Fibaro FGBHFS-001 and Samsung SmartThings’ Samsung GP-U999SJVLCAA. So, if you have an existing smart-home system, make sure you pick up the right sensor for it. If you don’t have an existing smart-home system, consider an option like Govee Wireless, which can monitor up to 10 sensors using its included gateway. Even simpler than that, the SimpleSENCE Freeze Detector has integrated Wi-Fi functionality, so you can connect directly to the app, without a gateway.

Temperature Sensing: For many users, this might be a useless extra, but for hydroponic gardeners running indoor grow lights or classic car collectors monitoring their storage garage during winter, being able to monitor the ambient temperature of a room at the same time as the moisture on the floor is a huge bonus. The SimpleSENCE Freeze Detector and iHome iSB02 are two multi-function options that can do just that.

4. Govee Wireless

5. Fibaro FGBHFS-001

6. Zircon Leak Alert

7. Moen Flo 920-004

8. SimpleSENCE Freeze Detector

9. Instapark IN07A

10. Samsung GP-U999SJVLCAA

Who Needs A Water Leak Sensor?

Keeping paintings away from any sort of moisture is an important part of caring for one's art collection.

Water leak sensors come with different features and capabilities, but most detect water in the same way. When water is present, its electrical conductivity decreases the resistance of two contacts on a particular strip on the sensor. When these tools sense water, they sound an alarm so that the user can fix the leak before it causes major water damage. They're most commonly used in areas that contain reserves of water, like rooms with water tanks, drain pipes or ice machines, but they can be useful all over a home or business. Some are designed to measure the water level in things like pools and ponds, to prevent these from overflowing and flooding the surrounding area.

Art gallery owners cannot afford to go without a water leak detector. Keeping paintings away from any sort of moisture is an important part of caring for one's art collection. The tiniest amount of moisture entering a painting can drastically reduce its value. Anyone with a room that requires a lot of electrical equipment, like a recording studio, should have one of these tools because the combination of a small flood and electrical wires can be extremely hazardous. If your home has a washing machine, a water leak sensor is essential. Should the pipe that carries water to the unit burst, it can cause water damage inside of the walls, which can greatly hurt the structure of the home. Water damage inside of a wall can also cause a mold and mildew buildup, which can be dangerous to one's health.

If you live in an upstairs unit of an apartment building, failing to catch a leak before it turns into water damage can not only affect your home but that of the people beneath you. If your water leak damages a downstairs unit, you won’t have the luxury of taking your time to fix it; whether you can afford it or not, you will need to fix the damage immediately. Anyone who lives in a rainy climate should have a sensor, too, because a leaky roof can become weak over time, and even collapse.

Special Features To Look For

Setting up a water leak sensor is an important part of maintaining a vacation or secondary home. Some sensors have alarms that will sound for weeks, so even if you aren't on the property each day, you'll still likely catch the leak. Some alarms produce 100 decibels of sound, so there is little chance of not hearing them. The longer the detection cable, the higher the chances are that the sensor detects water. A system that comes with cable securing clips can help you make sure your sensor stays in place.

Some alarms produce 100 decibels of sound, so there is little chance of not hearing them.

Make sure your sensor has a long battery life; some can last up to three years, reducing your chances of missing a leak because of a dead battery. Just like a good smoke detector, many water leak sensors chirp to let you know when their battery is low. The most effective units can detect a leak even if only 1/32 of an inch of its strip has been touched by water. If you don't want unsightly devices cluttering already small rooms like bathrooms, but you need to monitor for leaks around your toilet, some sensors are extremely compact and barely noticeable.

If installing gadgets isn't your strong suit, look for a model that doesn't require any mounting; there are some you can simply place on the floor and turn on. Since leaks rarely wait for a homeowner to come home, you may consider getting a sensor that sends alerts to your phone and email. If you are buying a water leak sensor because you live in an area that's subject to severe weather including earthquakes, make sure it is shock-resistant in case it falls.

What You Need To Know About Water Damage

Water damage is not to be taken lightly. If your home isn't made entirely of moisture-resistant materials, then water can spread rapidly through your walls, floors, and roof. After the initial water damage occurs, mold can begin to grow within 24 to 48 hours. The only way to prevent mold is to dry out your property entirely before that 24 to 48-hour window.

There are three levels of water contamination. Level one is water that comes from a clean source, like a pipe leading to a dishwasher, and originates inside of a building. Level two also comes from inside of a building, but at this level, the water has permeated more of the property, seeping into the cabinets and walls. Level three is the most hazardous and includes water that comes from outside of the home, like from a sewage system or the ocean. The important thing to know, if your home has water damage, is that level one can become level three quickly.

Water mixes with other water in an instant, so if any of the leak inside of your home mixes with water that has come in from outside, then you are at a level three contamination. This can cause serious health hazards, which is another reason you must fix water damage immediately.

Kaivaan Kermani
Last updated by Kaivaan Kermani

Kaivaan grew up in a little town called York in the north of England, though he was whisked off to sunny Jamaica at the age of 14, where he attended high school. After graduating, he returned to the UK to study electronic engineering at the University of Warwick, where he became the chief editor for the engineering society’s flagship magazine. A couple of uninspiring internships in engineering later however, and after some time spent soul-searching and traveling across Asia and East Africa, he he now lives and works in in Dubai.

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