Other leak detectors we like
First Alert L1 Wi-Fi Water Leak and Freeze Detector $62: Branding the first alert, this big flood sensor works with the First Alert or Resideo app and accessories. It has a 100 decibel alarm that sends push notifications and emails to alert you to any leaks and stops with the side button. The sensor was relatively slow on all tests, and push notifications only came when my phone was connected to Wi-Fi. A 5-foot water sensing cable can cover much larger areas. The detector connects directly to Wi-Fi, so you need the right signal. The sensor can also track temperature and humidity, but it is not very accurate (overestimating temperature and underestimating humidity). The two AA batteries provided are supposed to last up to two years.
$18 Switchbot Water Leak Detector:This rectangular detector triggered a quick alert on all tests with a 100 decibel alarm. With prongs up and down, the device quickly detected water. No hub is required as it connects directly to Wi-Fi. You can send push notifications and emails, but you'll need to set them up in the app. Unfortunately, the push notifications didn't pass when I came out of my home connected to a cell phone network instead of Wi-Fi. Smart Home Connectivity is excellent (Amazon Alexa, Google Assistant, and IFTTT) and allows you to set up automation in the Switchbot app. This makes this a versatile option, especially if you have other Switchbot devices. According to Switchbot, the two AAA batteries offered are good for up to two years.
Aidot Wines Water Leak Detector S1 Plus (3 Pack) $60: Set up when plug-in hubs are connected to 2.4-GHz Wi-Fi and place three circular detectors in the leaked location. You can configure up to 10 detectors to pair with the hub and send email and SMS messages above the app notifications when there is a leak. The probes on the bottom of each detector are very far apart and require 2 mm of water before the alarm is triggered. The stable IV drip on the top didn't go away, but as soon as water had accumulated underneath, the alarm went off. The alarm can be up to 100 dB, but I like the ability to fine-tune the volume and duration of the alarm. You can cancel the alarm via the app or by pressing the hub button. These detectors will collect suitable CR2 batteries for up to one year, and there will be signs in the app when the app dies. When I removed the battery from one of them, the app took several hours and updated it to display it as offline. One final drawback is that the hub is circular, which can block adjacent outlets. IFTTT support is a potentially convenient addition that can trigger water to block water or flash light when a leak is detected.
Aqara Water Leak Sensors for $19: This Zigbee sensor is best used with Apple's HomeKit and requires an Aqara Hub (sold separately). The company doubles as a hub and manufactures excellent security cameras that offer all kinds of smart home sensors. These small circular leakage sensors are very low to the ground, so just 0.5 mm of water below is enough to trigger the alarm. It cannot be dripped over, but an iPhone notification will trigger as soon as water pools underneath the probe is located. You can also play alarms on connected hubs and trigger automation via the home kit. The sensor ingests a CR2 battery and can last up to 2 years.
Stitching with a $25 Monopris leak sensor: This affordable water leak detector has a design similar to the top pick. The body is round, has metal feet to detect water pooling, and slots into the bracket for wall mounting. Comes with a coin-sized plug-in extension up to 3.8 feet. Both the main detector and the extension were quick to fire alarms when it got wet and send notifications to the phone (but the on-device alarms aren't that big). Use a single CR2 battery, display the remaining power in the app and warn you when it's time to change the battery. Unfortunately, the app is basic and poorly translated. I had to dry the detector and stop the alarm, and it took too long to warn me when I went offline (oddly, the offline detector can be toggled by default in the app settings, so I had to turn it on). You can make this a little cheaper by purchasing directly from Monopris.
Avoid leak detectors
I had no great experience with all the leak detectors I tested.
$12 Swann Leak Alert Sensor: This battery-powered water detector (two AAAs) is reasonably priced, but I had a terrible time setting it up. Your phone should be on 2.4-GHz Wi-Fi, but still required multiple attempts to connect. Frustratingly, the app doesn't have any options and you need to remove the screw panel to reset it. I got an alert to my phone about a minute after I immersed the sensor, but the Swann app is slow and clunky.
