The cheapest sensor in the house guards the most expensive damage · review
The only detector here that says how little water it needs — half a millimeter — and the only one that must stay within thirty-three feet of its hub.
The conclusion Half a millimeter is the only sensitivity figure on this shelf and it is the right thing to compete on — a film of water across a tile rather than a puddle, which is the difference between catching a weeping fitting and mopping a floor. IP67, a rust-proof coating, and automations that can close a valve. The constraint is severe and stated twice: the sensor must sit within thirty-three feet of an Aqara hub that is not included and cannot be a third party's.
No battery life. No siren of its own. No probe on a lead. No cable.
The only sensitivity figure on this shelf.
Nought point five millimeters is a film across a tile, not a puddle.
That is what a failing compression fitting or a perished washing machine hose produces for hours before anything visible happens.
This shelf’s buying tip says the same thing from the other side: a sensor in the middle of the floor reports a leak that has already spread.
No other detector here publishes a sensitivity, so with the rest you cannot know whether a slow drip will register at all.
And it is the thing to plan around.
Ten meters between the sensor and the hub. Ten meters between the hub and the router. Same local network.
A sensor belongs behind a washing machine or at the back of a cellar. The hub then has to be nearby, not in a living room on another floor.
Zigbee does mesh through other mains-powered Aqara devices, which helps in a house full of them.
Another maker on this shelf claims 2,034 feet on LoRa. Measure before buying three of these.
Which is more honest than most.
Compatible models named. Hubs from other brands will not work.
And then the sentence aimed at exactly the person who would try it: Zigbee2MQTT and comparable third-party USB dongles are not officially supported, and functionality may be limited or unavailable.
Already running Aqara: this is a three-pack of sensors. Otherwise it is a platform.
Which is the right rating for the job.
Dust-tight and able to survive temporary immersion — a sensor meant to sit in water should be.
The coating is the second half: a leak detector spends its life in a damp cupboard whether or not it ever sees a leak.
On sale at around $55 on the American Amazon store at the time of checking.
Prices and availability are what Keepa reported on the date this page was updated; both move.
Prices quoted in this text were read on October 8, 2026. The live price is at the top of the page.
| Sensitivity | Detects water levels as low as 0.5 mm (0.02 in), about 0.02 inch — stated, and the ONLY sensitivity figure on this shelf. It is the figure that distinguishes a sensor that catches a weep from one that waits for a puddle: half a millimeter is a film, not a pool, and this shelf's buying tip is exactly about catching water before it spreads |
|---|---|
| Range | The sensor must be kept within 10 meters (33 ft) of the Aqara Zigbee hub, AND the hub within the same range of the Wi-Fi router, on the same local network — stated twice, in two separate bullets. It is the shortest range on this shelf by a wide margin: another maker here claims 2,034 ft, a factor of sixty |
| Requires | An Aqara Hub, sold separately and NOT compatible with hubs from other brands, with the compatible models listed — M2, M1S, E1, M1S Gen2, G2H Pro, G2H on 2.4 GHz, or Camera Hub G3 on 2.4/5 GHz. Aqara also states that Zigbee2MQTT and comparable third-party dongles are not officially supported |
| Alerting | Both, through the hub: an instant phone alert AND the local alarm on the Aqara Hub. The sensor itself makes no sound, so the noise happens wherever the hub is rather than where the water is |
| Automation | Triggers other Aqara devices on detection, stated — which is the route to a shut-off valve, a light or a siren, and the reason to own the ecosystem. Three detectors on this shelf name or imply valve integration |
| Ratings | IP67 housing with a rust-proof exterior coating, stated. Dust-tight and able to survive temporary immersion, which is the right rating for a sensor meant to sit in water |
| Sensing element | Highly sensitive probes on the body, with no wiring and no screws — placeable on any flat surface. No remote probe and no cable |
| Battery | Not published. No cell type, no count and no runtime appears; Aqara only says to remove the battery tab before use and to check the battery level if the device does not work. At least four of the fourteen detectors here publish a figure |
| Supplied | Three sensors at fifty-five dollars — about eighteen dollars each, and the most expensive per sensor on this shelf |
| Amazon reference | B09WQPJBTQ |
| EAN | 6970504218314 |
Because it is the difference between catching a weep and finding a flood. Half a millimeter of water is a film across a tile, not a puddle — which is what a failing compression fitting or a perished washing machine hose produces for hours before anything visible happens. This shelf's buying tip is about the same thing from the other side: a sensor in the middle of the floor reports a leak that has already spread. No other detector on this shelf publishes a sensitivity at all, so with the rest you cannot know whether a slow drip will register.
It is the thing to plan around, and Aqara states it twice. Ten meters between the sensor and the hub, and ten meters between the hub and the router, on the same network — which for a sensor that belongs behind a washing machine or at the back of a cellar means the hub has to be nearby, not in a living room on another floor. Zigbee does mesh through other mains-powered Aqara devices, which extends it in a house full of them. Another maker on this shelf claims 2,034 feet on LoRa. Measure the distance before buying three of these.
A purchase, a model check and no shortcuts. Aqara names the compatible hubs — M2, M1S, E1, M1S Gen2, G2H Pro, G2H and the Camera Hub G3 — states that hubs from other brands will not work, and goes further than most by saying that Zigbee2MQTT and comparable third-party USB dongles are not officially supported and that functionality may be limited. That last sentence is aimed at exactly the person who would try, and it is honest. For a household already running Aqara the hub is fitted and this is a three-pack of sensors; for anyone else it is a platform.
Between security devices of the same category and nearby price. Shown: what they all state. A half-filled column says nothing.
| Model | Price | Alerting | Sensing element | Battery |
|---|---|---|---|---|
| Aqara TZ-005 Water Leak Sensor, Zigbee, 3-pack | $55 | Both, through the hub: an instant phone alert AND the local alarm on the Aqara Hub. The sensor itself makes no sound, so the noise happens wherever the hub is rather than where the water is | Highly sensitive probes on the body, with no wiring and no screws — placeable on any flat surface. No remote probe and no cable | Not published. No cell type, no count and no runtime appears; Aqara only says to remove the battery tab before use and to check the battery level if the device does not work. At least four of the fourteen detectors here publish a figure |
| YoLink YS1603+4YS7903 Leak Sensor 1 kit, 4 sensors and a hub | $60 | Remote only, and stated outright: "Leak Sensor 1 has NO BUILT-IN SIREN; add SpeakerHub or a YoLink siren for audible or spoken alerts if desired." This shelf's introduction makes local versus remote the first distinction worth understanding, and this is the only listing on this shelf that declares its own side of it rather than leaving you to infer it from silence | Base contacts. No probe and no sensing cable, where one detector on this shelf supplies a 5 ft cable extendable to 500 ft | NOT PUBLISHED. No cell type, no count and no runtime appears, where the maker's own Sensor 4 on this shelf states 2 AAA and up to five years. At least four of the fourteen detectors here publish a figure |
| RESIDEO CHW3610W8001 L1 Wi-Fi water leak and freeze detector | $62 | Both: a 100 dB alarm and LED status lights at the unit, plus mobile push and email notifications. One of four detectors on this shelf to publish a decibel figure and do both jobs | A 5-foot cable sensor that detects water along its ENTIRE LENGTH, with additional cables extending the run to 500 feet — stated. This shelf's introduction names exactly this as the second thing worth understanding: feet on the base detect water that reaches the unit, a sensing cable detects water somewhere awkward. At least seven of the fourteen detectors on this shelf are base contacts; this is the one that can be looped round a boiler or laid along a wall | Not published. The device is described as battery-operated with no cell type, no count and no runtime, where four detectors on this shelf publish a figure and two of those claim five years |
| Flood Buzz FB-6-C small water leak alarm, 6-pack | $46 | Local only, and completely: no app, no hub, no radio, no phone alert. This shelf's introduction says a standalone sensor sounds where it is, which is useless if the leak starts while you are away — this is the purest example of that trade on the shelf, and the lowest-maintenance one | Two metal prongs on the base, sounding the moment water touches them, with explicit placement advice: lay the prongs flat on the floor in the most likely path of a leak — directly behind a toilet, under a supply line, or at the low point of a drain pan — for the fastest response to even a slow drip | An internal 12 V battery sealed at the factory and NOT user-replaceable, with up to 3 years of active life — and a REPLACE-BY DATE STAMPED ON THE HOUSING. That stamp is unique on this shelf: a sealed battery with no visible expiry is a detector that silently stops working, and this one carries its own reminder |
Details checked on October 8, 2026.
An Aqara household with the hub nearby, where half a millimeter of water should start an automation
Amazon reports what buyers took in the month before this page was last checked: at least 500.
The figure is a floor, rounded by Amazon, and read through Keepa — it says what buyers picked, not what a maker claims.
Specifications: the manufacturer sheet for home security products and the matching Amazon product page. Prices and availability: Keepa. Every figure on this page names its source.
85 dB · two floor probes · stands on the floor · basement, laundry, kitchen, utility room
A standalone water alarm that stands on the floor with two probes underneath. ABUS states an 85 dB tone that sounds as long as the probes are in contact with water or another conductive liquid.
Best for: The floor beside a washing machine, a dishwasher or a water heater.
90 dB · three units · two electrodes on the base · wall or floor · ABS
Three water alarms at 90 dB with two electrodes on the base, which GOMETY states trigger immediately on contact with water. Wall or floor mounting, in ABS plastic, with no wiring or programming.
Best for: Covering three risks at once — the usual number in a house with a basement.
85 dB · sealed 10-year lithium battery · miniature floor sensor
A miniature floor sensor with a sealed lithium battery that SEBSON states lasts ten years. No battery to change, and no battery compartment to corrode.
Best for: A place you will not revisit — under a bath, behind a built-in appliance, beside a boxed-in water heater.
