Smart water shutoff valves (2026)
A smart water shutoff closes your main water supply when it detects a leak, so a burst pipe or failed hose becomes a puddle instead of a flooded floor. There are two kinds: valves a plumber cuts into your main line, which watch the flow of water through the whole house, and motor kits that clamp onto the quarter-turn valve you already have and close it when a leak sensor gets wet. This page compares both, plus one monitor that warns but can't shut off. Every spec is from the maker's page, read on the date in each card's notes; we haven't used these ourselves.
By Tom Calder · Updated November 9, 2026 · 7 products, 6 of 7 price-tracked
Our picks
Photo: AmazonMoen Flo 3/4 in
Whole-home auto shutoff on a 3/4 in main
as of Nov 9, 2026, 11:40 AM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Photo: AmazonYoLink Shutoff Kit
DIY shutoff on an existing ball valve
as of Nov 9, 2026, 11:40 AM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Photo: AmazonPhyn Smart Water Assistant
A no-plumber way to watch for leaks
as of Nov 9, 2026, 11:40 AM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.All 7 compared
| Valve | Pipe size | Install | Detects by | Connects by | Price |
|---|---|---|---|---|---|
3/4 in or smaller pipe · Plumber install (cuts into main) · In-line flow, pressure, temperature · Wi-Fi 2.4 GHz + AC power Whole-home auto shutoff on a 3/4 in main | 3/4 in or smaller pipe | Plumber install (cuts into main) | In-line flow, pressure, temperature | Wi-Fi 2.4 GHz + AC power | $559 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched An in-line valve that watches flow, pressure and temperature and can close your main automatically. Moen recommends a plumber because the main is cut. Best for Whole-home auto shutoff on a 3/4 in main Good
Worth knowing
Who shouldn't buy it: Don't buy it if your main pipe is larger than 3/4 inch. | |||||
 1-1/4 in or smaller pipe · Plumber install (cuts into main) · In-line flow, pressure, temperature · Wi-Fi 2.4 GHz + AC power Whole-home auto shutoff on a larger main | 1-1/4 in or smaller pipe | Plumber install (cuts into main) | In-line flow, pressure, temperature | Wi-Fi 2.4 GHz + AC power | $999.91 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The same in-line shutoff as the 3/4 in model for mains up to 1-1/4 in. Plumber install recommended. Best for Whole-home auto shutoff on a larger main Good
Worth knowing
Who shouldn't buy it: Don't buy it if you have a 3/4 in main and don't need the larger body. | |||||
Pipes up to 1-1/4 in (1 in NPSM ends) · Plumber install (cuts into main) · Pressure-wave + ultrasonic flow · Wi-Fi; outlet within 12 ft Whole-home shutoff with freeze warnings | Pipes up to 1-1/4 in (1 in NPSM ends) | Plumber install (cuts into main) | Pressure-wave + ultrasonic flow | Wi-Fi; outlet within 12 ft | |
Our verdictOur verdictResearched An in-line shutoff for mains up to 1-1/4 in with leak alerts, freeze warnings and remote shutoff. Licensed plumber recommended; adapters sold separately. Best for Whole-home shutoff with freeze warnings Good
Worth knowing
Who shouldn't buy it: Don't buy it if your main is over 1-1/4 inches (look at Protect XL) or you want no outlet near the main. | |||||
 3/4 in and 1 in (1-1/4 in version sold) · Plumber install recommended · Ultrasonic flow + temperature · App (Tuya Smart Life); battery backup A lower-profile in-line shutoff option | 3/4 in and 1 in (1-1/4 in version sold) | Plumber install recommended | Ultrasonic flow + temperature | App (Tuya Smart Life); battery backup | $279.98 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. |
Our verdictOur verdictResearched An in-line monitor and shutoff valve with ultrasonic flow sensing, a touch panel and a rechargeable backup battery. Maker recommends professional installation. Best for A lower-profile in-line shutoff option Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want a brand with a published insurer program. | |||||
 3/4 in or smaller pipe · Plumber install (cuts into main) · In-line flow + 3 leak detectors · Wi-Fi 2.4 GHz + AC power Main shutoff plus point-of-leak sensors | 3/4 in or smaller pipe | Plumber install (cuts into main) | In-line flow + 3 leak detectors | Wi-Fi 2.4 GHz + AC power | $698.98 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The 3/4 in in-line shutoff plus three Flo detectors you place near the water heater, washer or sump. Detectors cover sources the in-line valve cannot see. Best for Main shutoff plus point-of-leak sensors Good
Worth knowing
Who shouldn't buy it: Don't buy it if your main is larger than 3/4 inch. | |||||
3/8 in hot and cold angle stops · DIY under one sink · Pressure sensing, freeze warnings · Wi-Fi; no hub or subscription A no-plumber way to watch for leaks | 3/8 in hot and cold angle stops | DIY under one sink | Pressure sensing, freeze warnings | Wi-Fi; no hub or subscription | $441.94 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A DIY under-sink monitor that sends leak and freeze alerts. It cannot turn the water off. Best for A no-plumber way to watch for leaks Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want the water shut off automatically. | |||||
7. YoLink Water Shutoff Kit: Valve Controller, EVO Operator, 3 Leak Sensors and Hub Best DIY shutoff kit Fits an existing ball valve · DIY: fits on existing ball valve · Leak sensors only (3); no flow sensing · YoLink hub (LoRa) DIY shutoff on an existing ball valve | Fits an existing ball valve | DIY: fits on existing ball valve | Leak sensors only (3); no flow sensing | YoLink hub (LoRa) | $216.57 at Amazon as of Nov 9, 2026, 11:40 AM ET · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A motor that turns your existing quarter-turn valve, plus three leak sensors and a hub. It reacts to wet sensors, not to flow, so a burst in an unsensed spot is not detected. Best for DIY shutoff on an existing ball valve Good
Worth knowing
Who shouldn't buy it: Don't buy it if your main shutoff is a gate valve or is stiff or boxed in. | |||||
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Before you buy
In-line valves (Moen Flo, Phyn Plus/Protect, Frizzlife LP365) go into the main pipe and sense flow, so they can catch a leak anywhere in the house, even where you have no sensor. Moen says installing Flo "requires removing a section of your main water pipe" and recommends a plumbing professional; Phyn recommends a licensed plumber.
Pipe size: check your main before you buy.
Moen's 900-001 is for 3/4 inch or smaller pipe and the 900-002 for up to 1-1/4 inch; Phyn says its valve suits mains 1-1/4 inch or smaller.
Power and Wi-Fi: Moen Flo needs 2.4 GHz Wi-Fi and an outlet within 10 feet; Phyn needs an outlet within 12 feet.
Frizzlife lists a rechargeable backup battery. Plan where the valve goes before the plumber arrives.
Motor kits (YoLink) turn an existing ball valve, so no plumbing is cut.
YoLink says the valve must move freely and have room for the actuator. They react only when a leak sensor gets wet, so a leak where there's no sensor goes unnoticed.
Monitor-only devices like the Phyn Smart Water Assistant install under a sink and alert you to leaks and freezing risk, but they can't close the water off.
Insurance: Chubb's own page says its clients "may be eligible to receive a discount on your insurance policy" for a water shutoff device, and Phyn offers Chubb clients a discount on the device. Moen says to ask your insurer about discounts and offers an insurance letter in its app. Other carriers vary by state and policy, so ask yours before counting on a saving.
Know your manual shutoff.
Whatever you buy, everyone at home should know where the main water valve is and how to close it.
We verify every product's specifications against at least two independent sources, re-check its US price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labeled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test. When two products are close, commission can decide which one we pick. A clearly better product always wins. Read our full methodology →
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Common questions
Do I need a plumber to install a smart water shutoff?
For in-line valves, the makers say yes: Moen calls Flo installation an advanced project that removes a section of your main pipe and recommends a plumbing professional, and Phyn recommends a licensed plumber. Motor kits like YoLink's clamp onto an existing ball valve and are DIY if the valve turns freely.
Will my home insurance give me a discount?
Some insurers do. Chubb's own page says clients may be eligible for a discount on their policy for a water shut-off device, plus a discount on the device. Moen says to contact your insurer about discounts and rebates. Ask your own insurer: it depends on the company, state and policy.
Does a smart shutoff work in a power outage?
It depends on the model. Phyn says its valve won't turn your water off during a power loss unless it was already closed. Moen sells a battery backup for Flo in some bundles, and Frizzlife lists a built-in rechargeable battery. Check before you rely on it during storms.
What's the difference between a shutoff valve and a leak sensor?
A leak sensor tells you water is on the floor where the sensor sits. A shutoff valve can stop the water. Flow-sensing valves can catch a leak anywhere; sensor-triggered kits only act when one of their sensors gets wet.
Can a shutoff valve stop a basement flood?
Not from rain or groundwater. Moen says Flo can't protect against flooding from heavy rain, an overflowing sump pump or a leaky roof. For those, look at a sump pump with battery backup.