Quick picks
| Product | Best for | What to know |
|---|---|---|
| Moen Flo 3/4-inch Smart Water Shutoff | Whole-home water monitoring and automatic shutoff | Inline installation on the main water pipe; confirm size and plan for professional installation |
| YoLink Water Leak Sensor 4 + SpeakerHub kit | Several local leak-prone areas and long-range sensor coverage | This kit includes sensors and a hub, not a main-line shutoff valve |
| Shelly Flood Gen4 | An affordable cable sensor for a connected smart home | Detects water at the sensor cable; the sensor alone does not shut off the main supply |
Top recommendations
Best for: Whole-home water monitoring with automatic shutoff
Moen Flo 3/4-inch Smart Water Shutoff, Model 900-001
Unlike a spot sensor, Flo is installed inline on the home's main water pipe. It monitors water flow, pressure, and temperature, sends alerts, and can automatically close the valve when it detects a leak or abnormal use. PCMag rates it 4.0 Excellent and says it needs about 7 to 10 days to learn typical household usage; it also notes that professional installation is required. The 3/4-inch Amazon listing is one pipe-size option, so confirm your home's pipe diameter before ordering. Flo needs nearby AC power. Some Moen bundles add local leak detectors, battery backup, or a FloProtect service plan; those accessories and terms are not guaranteed with this standalone valve listing. PCMag’s test Moen Flo features and sizing
- Monitors water at the main line rather than depending on a sensor being placed beside every appliance
- Can send remote alerts and shut off the whole-home supply when its monitoring detects a serious anomaly
- Provides water-use monitoring and daily MicroLeak checks in addition to leak alerts
- Requires plumbing work and professional installation, adding cost and planning
- Must be sized to the home's water pipe and installed near an AC outlet
- The standalone valve does not include the battery backup or extra local sensors shown in some bundles
Best for: Monitoring several spots, including basements and outbuildings
YoLink Water Leak Sensor 4 3-Pack with SpeakerHub
Wirecutter found the YoLink Water Leak Sensor 4 responsive in testing, detecting leaks within two seconds. The Amazon kit includes three sensors and a SpeakerHub, with a loud alarm, freeze alerts, and app notifications. YoLink's long-range radio can help connect sensors in locations where ordinary Wi-Fi does not reach well, but the hub itself needs a stable 2.4-GHz Wi-Fi connection. The included sensors detect water at local spots; this kit does not include a valve to shut off the home's main supply. The listing includes a limited number of free SMS alerts per month, with paid options if you need more. Wirecutter’s sensor test YoLink starter-kit information
- Three sensors and the required hub are included, making it easier to cover multiple leak-prone areas
- A hub-based radio link is useful for sensors placed far from the router or across floors
- The kit combines phone alerts with an audible alarm and freeze warnings
- The hub needs Wi-Fi and a power outlet, even though the sensors communicate with it over YoLink's long-range protocol
- Local leak alerts do not automatically close a water valve with this kit alone
- Additional SMS alerts may require a paid plan after the included monthly allowance
Best for: A lower-cost cable sensor for a smart-home setup
Shelly Flood Gen4 Smart Flood Sensor
PCMag names the Shelly Flood Gen4 its affordable leak-detector pick. It uses a cable sensor that can be placed along an appliance or other vulnerable area, and PCMag says the cable can be extended to cover a longer run. The device supports Wi-Fi, Bluetooth, and Zigbee, with Matter and popular smart-home platform support listed by Shelly and the Amazon listing. It is a local water sensor, not a whole-home flow monitor, and it does not include a main-line shutoff valve. It also lacks a temperature sensor. PCMag’s tested picks Amazon listing
- Costs less than a whole-home valve and focuses on detecting water where a cable is placed
- The cable can be extended to cover more of a leak-prone path
- Broad wireless and smart-home support makes it a flexible fit for an existing connected home
- Protects only the area covered by its cable, so other likely leak points need their own sensors
- Does not monitor total household water flow or shut off the main water supply by itself
- No temperature sensor for freeze alerts
How to choose a water leak detector
- Decide whether you need local alerts or a whole-home shutoff. A puck or cable sensor detects water where it is placed. A main-line monitor can watch overall flow and, on supported systems such as Moen Flo, close a valve. These are different levels of protection, not interchangeable features.
- Map likely leak points before choosing a sensor count. Common spots include under sinks, behind toilets, beside a washing machine or dishwasher, near a water heater, in a sump-pump pit, and below an HVAC condensate line. Add sensors where a leak could start unnoticed.
- Check what needs Wi-Fi, a hub, and an outlet. Hub-based sensors often use a separate radio to reach distant rooms, but the hub still needs power and internet for remote phone alerts. Confirm whether the kit requires a 2.4-GHz Wi-Fi network.
- For a main-line valve, measure first and use a qualified installer. Confirm the pipe size, available space, and power access. Ask a plumber to check any unusual plumbing layout before installing an automatic shutoff.
- Test the alerts and keep sensors maintained. Place each sensor on a dry floor where water will reach its contacts, name it for its location in the app, and test it after setup. Replace batteries when prompted and check periodically that the hub stays online.
A smart leak sensor is an early-warning layer, not a substitute for fixing worn hoses, inspecting plumbing, or responding to alarms. For broad protection, some homeowners use both a main-line monitor and smaller sensors beside individual appliances.
Related guides: smart thermostats for heat pumps, no-subscription outdoor security cameras, Matter smart plugs, robot vacuums for pet hair.
FAQ
Do smart water leak detectors shut off the water automatically?
Some do, but many only sound an alarm or send an app alert. The Moen Flo valve installs on the main water line and can close it automatically. The YoLink sensor kit and Shelly Flood Gen4 listed here detect water locally but do not include a main-line shutoff valve.
What is the difference between a leak sensor and a whole-home water monitor?
A leak sensor detects water at a particular point, such as under a sink. A whole-home monitor is installed on the main water line and analyzes water flow through the house. A whole-home shutoff system can close that valve when it detects a likely leak.
Where should I put water leak sensors?
Start near appliances and plumbing connections that could leak unnoticed: under sinks, near toilets, behind a washing machine, beside a water heater, near a dishwasher, and around sump pumps or HVAC drain pans. Put sensors where water will reach the contacts before it spreads.
Does the Moen Flo valve need a plumber?
PCMag says professional installation is required. Before buying, confirm the correct pipe size and make sure there is room and an AC outlet near the main water line. If your plumbing setup is unusual, ask a licensed plumber to assess compatibility. PCMag’s guide Moen sizing information
Will a leak sensor still work if the internet goes down?
It depends on the model. Some sensors or hubs can sound a local alarm without internet, while remote app alerts need a working connection. Check the manufacturer's offline behavior and place a sensor with a local audible alarm in areas where you may not hear a phone notification.