Best water leak and freeze detectors (2026)
A frozen pipe often gives no sign until it thaws and leaks. A water sensor on the floor by the water heater, the washer or under a sink warns you when water appears, and many also warn when the room gets close to freezing, which is when you can still act. This page compares leak sensors sold in the US on whether they send a freeze alert, how they reach you (siren, app or both) and what they run on. We haven't used them ourselves; every figure is the maker's or the listing's.
By Tom Calder · Updated November 1, 2026 · 5 products, prices indicative
Our picks
Kidde leak + freeze
A low-cost Wi-Fi leak sensor that also warns about near-freezing temperatures
YoLink Sensor 4 kit
Covering several spots (basement, laundry, under sinks) with one hub
Moen Flo detector
A leak detector that can later link to a Moen whole-home shutoff valve
All 5 compared
| Detector | Type | Freeze alert | Alerts by | Hub | Power | Price |
|---|---|---|---|---|---|---|
Wi-Fi leak and freeze detector · Yes, near-freezing alert (maker) · App alert + loud beep (maker) · Wi-Fi, no hub (maker) · Battery-powered (maker) A low-cost Wi-Fi leak sensor that also warns about near-freezing temperatures | Wi-Fi leak and freeze detector | Yes, near-freezing alert (maker) | App alert + loud beep (maker) | Wi-Fi, no hub (maker) | Battery-powered (maker) | |
Our verdictOur verdictResearched A small Wi-Fi detector from a name known for smoke and CO alarms. Kidde says it watches for water and for temperatures approaching freezing, and tells your phone through its app with no hub to buy. The maker page does not give the freeze temperature or battery type, so read the user guide before relying on it in a cold spot. Best for A low-cost Wi-Fi leak sensor that also warns about near-freezing temperatures Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want to set your own freeze temperature or need a sensor cable to reach under appliances. | ||||||
Long-range leak sensors, 4 + hub · Yes, adjustable low-temp warning (maker) · App alerts + sounder, 105 dB (listing) · Needs YoLink hub, included in kit · 2 AAA alkaline each, included (maker) Covering several spots (basement, laundry, under sinks) with one hub | Long-range leak sensors, 4 + hub | Yes, adjustable low-temp warning (maker) | App alerts + sounder, 105 dB (listing) | Needs YoLink hub, included in kit | 2 AAA alkaline each, included (maker) | |
Our verdictOur verdictResearched A four-sensor kit with a hub that talks to the sensors over YoLink's own long-range radio, not your Wi-Fi. YoLink says each sensor has a configurable low-temperature warning as well as a leak sounder. The catch is the hub: it must be plugged in and joined to your network for app alerts. Best for Covering several spots (basement, laundry, under sinks) with one hub Good
Worth knowing
Who shouldn't buy it: Don't buy it if you only need one sensor and want the simplest setup without a hub. | ||||||
Wi-Fi leak, humidity, temp detector · Yes, low-temperature alert (maker) · App, text, call or email (maker) · Wi-Fi, no hub; 2.4 GHz (maker) · 1 CR123A lithium, up to 2 yrs (maker) A leak detector that can later link to a Moen whole-home shutoff valve | Wi-Fi leak, humidity, temp detector | Yes, low-temperature alert (maker) | App, text, call or email (maker) | Wi-Fi, no hub; 2.4 GHz (maker) | 1 CR123A lithium, up to 2 yrs (maker) | |
Our verdictOur verdictResearched Moen's stand-alone Wi-Fi detector that also tracks room temperature and humidity, with alerts by app, text, call or email. Moen says it can pair with its Flo shutoff valve, which is sold separately. Moen's pages give no freeze threshold, so check the setting in the app. Best for A leak detector that can later link to a Moen whole-home shutoff valve Good
Worth knowing
Who shouldn't buy it: Don't buy it if you have a 5 GHz-only Wi-Fi network or just want a cheap local alarm. | ||||||
Wi-Fi detector + 5 ft cable sensor · Yes, frozen-pipe alerts (maker) · App alert, LEDs, 100 dBA alarm (maker) · Wi-Fi, no hub (maker) · 2 AA batteries (maker) Cable-sensor coverage along a wall or under a water heater | Wi-Fi detector + 5 ft cable sensor | Yes, frozen-pipe alerts (maker) | App alert, LEDs, 100 dBA alarm (maker) | Wi-Fi, no hub (maker) | 2 AA batteries (maker) | |
Our verdictOur verdictResearched A Wi-Fi detector with a 5-foot cable sensor, so it can catch water along a stretch of floor rather than one spot. Resideo says it warns of leaks and frozen pipes by phone and sounds a 100 dBA alarm itself. It is rated down to 32 F, so keep it indoors. Best for Cable-sensor coverage along a wall or under a water heater Good
Worth knowing
Who shouldn't buy it: Don't buy it if you need a sensor for an unheated space that will drop well below freezing. | ||||||
Battery siren alarm, no app · No · 110 dB siren only (maker) · None, no Wi-Fi · 9V battery (manual) A cheap, loud alarm for a basement where you are home to hear it | Battery siren alarm, no app | No | 110 dB siren only (maker) | None, no Wi-Fi | 9V battery (manual) | |
Our verdictOur verdictResearched A plain battery alarm: no Wi-Fi, no app, no freeze sensing, just a very loud siren on a 6-foot detachable sensor wire. Basement Watchdog says it sounds at 1/32 inch of water. It is a good backstop beside a smart sensor, but it cannot tell you anything when you are away. Best for A cheap, loud alarm for a basement where you are home to hear it Good
Worth knowing
Who shouldn't buy it: Don't buy it if you want a warning on your phone or for pipes at risk of freezing. | ||||||
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Before you buy
Freeze alert.
Many sensors report temperature and warn when it drops near freezing. That's the alert that lets you act before a pipe splits. The table shows which do.
Siren, app or both.
A siren is heard by whoever's home. An app alert reaches you away from home but needs Wi-Fi and power at the house. Sensors that work through a hub need the hub plugged in too.
Where to put them.
Next to the water heater, washing machine, sump pump, under kitchen and bathroom sinks, and in any space with pipes that have frozen before.
Check the operating range.
Some sensors are rated for indoor use only and down to about 32°F (YoLink and Resideo both give that range), so for a crawl space, garage or other spot that really freezes, read the maker's range first.
Batteries.
Most run on small batteries (the type is in the table). Check them each fall when you check your smoke and CO alarms.
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 water leak detectors detect freezing?
Many do: they measure the air temperature where they sit and warn when it drops near freezing. Others only detect water. The table shows which give a freeze alert.
Where should I put a water leak sensor?
On the floor beside the water heater, washer and sump pump, under kitchen and bathroom sinks, and anywhere pipes run through cold space, like a crawl space or an unheated basement.
Do leak detectors need Wi-Fi?
Wi-Fi or hub models need it to send app alerts; a simple battery alarm just sounds a siren. If you want an alert when you're away, you need the connected kind, and the house needs power and internet.
What temperature should I leave the heat at when I'm away?
The Red Cross says to leave the heat on "set to a temperature no lower than 55° F."