The best water leak detectors

Who this is for

Point sensors are the cheapest insurance in the house, and the most misunderstood. A sensor does one thing: it tells you water has reached the spot where it sits. It will not see a pinhole inside a wall, a slab leak or a running toilet; for those you need a flow monitor on the main, covered in our smart water shutoff valve guide. What sensors do brilliantly is catch the appliance failures that cause most of the water losses we dry out: a water heater that let go at the bottom seam, a washer hose, a dishwasher pump seal, an icemaker line, an HVAC condensate pan, a sump pump that quit.

This guide is for anyone who wants phone alerts from those spots, and for anyone who wants sensors that can also close the main. We weight battery life and radio reliability heavily because a sensor with a dead battery in year two protects nothing, and because the places that flood are the places Wi-Fi does not reach.

Compared at a glance

Where to place sensors

Work from the appliances that fail hardest to the ones you would notice anyway. One sensor per spot; the first six cover most houses.

1. Water heater pan. A tank fails at the bottom and keeps refilling itself, so a 50-gallon heater can put hundreds of gallons on the floor overnight. Put the sensor or probe disc in the drain pan, not beside it. If the pan has a drain line, confirm it actually goes somewhere.
2. Washing machine. Behind or under the washer, below the supply valves. Braided hoses still burst; the drain hose jumps out of the standpipe. A probe cable lets the sensor body sit on the shelf while the probe lies on the floor behind the machine.
3. Under sinks. Kitchen first (dishwasher supply and disposal share the cabinet), then bathrooms. Set the sensor at the back of the cabinet under the trap, where a weeping compression nut drips.
4. Sump pit high-water line. Mount the sensor on the pit wall or hang a probe just below the rim, above the float's normal high point. If water reaches it, the pump has failed or cannot keep up. This is where long-range radios earn their keep; a pit under a slab is a Wi-Fi dead zone.
5. Behind the refrigerator. Icemaker and water dispenser lines are 1/4-in plastic or copper, and they fail quietly behind an appliance nobody moves for years.
6. HVAC drain pan. A clogged condensate line overflows the secondary pan in the attic or the closet; by the time the ceiling stains, the drywall is done. A probe disc in the pan beats a float switch that nobody tests.

Also worth a sensor: the dishwasher kick plate, a basement toilet, the boiler room, and the floor under a whole-house filter housing. In crawl spaces, put one at the lowest point and one near the main shutoff.

How to choose

Battery life and the year-three problem

We score battery life at 20% of the rubric because most sensors are dead when the leak comes. YoLink rates its Water Leak Sensor 1 at five-plus years on two AAA cells and Govee rates the 1s at up to five years on two AAA; both report battery level to the app. Ring quotes a maximum of three years on a 3 V lithium cell. Moen's detector runs about two years on a CR123A. Eve Water Guard plugs into the wall, so there is no battery to track, but it also cannot go anywhere without an outlet. Zircon's 9 V box does not publish a life figure and beeps when it is low.

Whatever you buy, put the battery date on the sensor with a marker and put a yearly reminder in your phone to press the test button.

Radios: why range matters more than Wi-Fi

The places that flood are basements, crawl spaces and pits, which is also where Wi-Fi fades. YoLink's LoRa sensors are rated at a quarter mile open air to the hub; we have seen them report from detached pump houses and from pits under slabs. Govee's 1s talks 915 MHz to its gateway, rated at 1,804 ft, which is plenty for a large house and most outbuildings. Ring's Z-Wave sensors reach 250 ft to the base station and ride a mesh of other Ring devices. Eve uses Thread. Moen's detector is pure 2.4 GHz Wi-Fi, which is fine for an upstairs laundry and risky for a crawl space.

The trade-off for long range is a hub. YoLink, Govee, Ring and Eve (for alerts away from home) all need one plugged in somewhere. The rubric gives a small bonus to no-hub designs because a hub is one more thing to lose power, but we would rather have a hub and a sensor that reports than no hub and a sensor that quietly dropped off the network.

Freeze alerts

Burst pipes from freezing are the single most expensive residential water loss we see, and they happen in garages, crawl spaces and cabins where nobody is standing. Ring's Flood and Freeze Sensor is built for it. Moen's detector reports temperature and lets you set an alert anywhere in its 0 to 140°F range, so a 38°F alert is a practical freeze warning, and it adds humidity alerts that catch a damp basement. Govee's 1s, YoLink's Sensor 1, Eve Water Guard and Zircon do not publish temperature reporting, so if freeze is your worry, buy accordingly or add a dedicated temperature sensor from the same ecosystem.

Probe cables and sensing discs

A probe or cable lets the electronics stay dry and high while the sensing element reaches the low spot: the bottom of a water heater pan, the back corner behind a washer, the inside of a sump pit. Moen includes a 48-in remote sensing disc and sells a 6-ft cable that chains up to three deep. Eve Water Guard is nothing but cable: 6.5 ft in the box, extendable to 490 ft, and it senses along the whole length, which is how you line a basement perimeter with one device. Govee sells a cabled variant of the 1s separately. YoLink's Sensor 1 and Ring's sensor have electrodes on the puck itself, so the puck sits in the water; YoLink's Sensor 2 adds a probe if you need one.

Local sirens

A loud sensor still matters when you are home. Govee's 1s is adjustable to 105 dB, Eve's siren is 100 dB, and Zircon's is 90 dB with no app at all. YoLink and Ring do not publish a siren rating for the sensor; Ring's base station does the shouting and YoLink sells a separate siren. For an occupied laundry room, loud wins. For a vacation home, nobody hears anything, so phone alerts and a shutoff valve are the only things that count.

How sensors pair with a shutoff valve

A sensor that can close the main is a different product from one that can only text you. Three of our picks can:

• YoLink: add the YoLink valve controller, which bolts onto your existing ball valve, and the sensors close it through local device-to-device pairing, with the power and internet down.
• Moen: the Smart Water Detector pairs with a Moen Flo on the main; a wet disc triggers the shutoff.
• Phyn: Phyn's Smart Water Sensor can be configured to have Phyn Plus shut off the water.

Govee, Ring, Eve and Zircon alert only. If you are starting from scratch and think you will ever want automatic shutoff, buy into one of the three ecosystems above. We compare the valves in our smart water shutoff roundup and the two big inline units in Moen Flo vs Phyn Plus.

What we skipped and why

Ring Alarm Flood and Freeze Sensor. Good if you already own a Ring base station, and the only pick with a dedicated freeze function, but it needs the base station and Ring notes a compatible subscription is required for alerts. It stays in the table for Ring households.

Zircon Leak Alert. A 90 dB local alarm with no connectivity. We keep a few in occupied rooms and rentals, and it is in the table, but it cannot win a category that is about alerts while you are away.

Aqara Water Leak Sensor. A solid Zigbee puck for Aqara hub owners; Eve took the slot because Eve publishes cable length, extension limit and siren rating on its own site and the long cable solves a problem pucks cannot.

Generic Wi-Fi pucks with no published battery life or range. If the manufacturer will not state battery life, we will not recommend it.

How we test and score

We do not run a sensor lab and we do not claim to. We place these on real water losses and in our own mechanical rooms, we read the manufacturer datasheets, and we score each product against the published rubric for this class: battery life (20%), phone alerts (15%), radio reliability (10%), freeze warning (10%), probe cable (10%), local siren (10%), temperature and humidity logging (10%), warranty (10%) and no hub needed (5%). Every spec comes from the manufacturer; where a value was not published we left it blank, and the coverage figure next to each score tells you how much of the rubric had data. We do not score on price.