The cheapest sensor in the house guards the most expensive damage · review
The only detector here with nothing to set up and nothing to connect — and the only one that prints its own expiry date where you can see it.
The conclusion Nothing to set up, nothing to pair, nothing to charge, and a replace-by date stamped on the case so you can see at a glance whether it still works — which on a sealed battery is the only honest design. At 1.75 inches it goes behind a toilet or under a kick plate where a connected sensor never would, and Flood Buzz tells you exactly where to lay the prongs. It is local only, 95 dB is the quietest here, and at three years the unit is finished.
No app. No hub. No radio. No phone alert. No freeze detection.
Which is the single most useful thing here.
A sealed battery is a silent failure. Every detector on this shelf with a built-in cell simply stops working one day, and nothing about it changes — it sits under the sink looking exactly as it did when it worked.
Flood Buzz stamps a replace-by date on the housing. A glance answers the question.
The five-year sealed detector on this shelf publishes a life and no date. The one with AAA cells can just be re-celled.
For the places you would never put a connected sensor.
This shelf’s buying tip says to put a sensor where water arrives rather than where you would notice it — and the awkward spots are also the worst radio spots. Behind a kick plate. Inside a cabinet. In a drain pan channel.
One point seven five inches across, no radio to fail, no account to lapse.
At eight dollars each you put six of them where you would never run a pairing procedure.
What it cannot do is tell you anything while you are out. This shelf’s introduction is blunt about that trade.
Which is rare on this shelf.
Ninety-five decibels, compared to an alarm clock, with best results close to the source inside a cabinet.
And then: place two units together, or move up to the Pro at 110 dB.
Two detectors here publish 105 dB, one publishes 100, and one of those lets you turn it down.
Flat on the floor, in the most likely path.
Directly behind a toilet. Under a supply line. At the low point of a drain pan.
That is the buying tip restated by the manufacturer, and no other listing on this shelf is this specific about placement.
“Under $8 a sensor”, then “roughly $9 per sensor”, in the same sentence.
Forty-six dollars for six is $7.67. The first figure is the right one.
On sale at around $46 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.
| Setup | None: a factory-installed, pre-tested battery is sealed inside, with no battery installation, no tools and NO APP. Open the box and set each unit on the floor near a water connection. It is the only detector on this shelf that works out of the box with nothing else bought, configured or paired |
|---|---|
| Alarm | Up to 95 dB at the leak location, compared by the maker to an alarm clock, with best results close to the water source inside an enclosed cabinet or under a sink. Flood Buzz also tells you what to do if it is not enough: place two units together, or move up to the Flood Buzz Pro at 110 dB. That is a maker naming its own product's limit and the remedy |
| Battery | 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 |
| Sensing element | 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 |
| Dimensions | 1.75 × 1.5 × 1.5 in — stated, and the only dimensions published on this shelf. Flood Buzz uses them properly: that size fits behind toilet bases, beneath dishwasher kick plates, inside cabinet corners and in HVAC drain pan channels where standard sensors cannot reach |
| Alerting | 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 |
| Reusability | Reusable after every leak: wipe the prongs dry and the unit works again until the replace-by date, stated |
| Supplied | Six alarms at forty-six dollars. The listing says "under $8 a sensor" and then "roughly $9 per sensor" in the same bullet; the arithmetic is $7.67, so the first figure is the right one |
| Maker | A patented design from Archetype Ltd., a family-owned company in New Jersey — stated, and the only named manufacturer and location on this shelf |
| Amazon reference | B005OQY5KG |
| EAN | 0857092002159 |
For the places you would never put a connected one, yes. This shelf's buying tip says to put a sensor where water arrives rather than where you would notice it, and the honest problem with connected detectors is that the awkward spots are also the worst radio spots — behind a kick plate, inside a cabinet, in a drain pan channel. This one is 1.75 inches across, has no radio to fail and no account to lapse, and at eight dollars you can put six of them where you would never run a pairing procedure. What it cannot do is tell you anything while you are out.
Because a sealed battery is a silent failure. Every detector on this shelf with a built-in cell stops working when that cell dies, and nothing about the unit changes — it sits there looking exactly as it did when it worked. Flood Buzz stamps a replace-by date on the housing, so a glance under the sink answers the question, and that is the single most useful thing on this page. The five-year sealed detector on this shelf publishes a life and no date; the one with AAA cells can simply be re-celled.
Inside a cabinet, probably; across a house, no — and Flood Buzz says so. The listing compares 95 dB to an alarm clock, states that the best results come from placing it close to the source inside an enclosed cabinet or under a sink, and then offers two remedies: put two units together, or move up to the Flood Buzz Pro at 110 dB. A maker naming its own product's limit is rare on this shelf. Two detectors here publish 105 dB and one publishes 100, and one of those lets you turn it down.
Between security devices of the same category and nearby price. Shown: what they all state. A half-filled column says nothing.
| Model | Price | Battery | Sensing element | Alerting |
|---|---|---|---|---|
| Flood Buzz FB-6-C small water leak alarm, 6-pack | $46 | 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 | 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 | 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 |
| GoveeLife H5059 water leak detector, 105 dB adjustable alarm, 5-pack | $43 | A built-in battery lasting 5 years with no frequent replacements, stated. Tied with the longest figure on this shelf — but built-in, so when the five years are up the detector is consumed rather than re-celled | Two sets of sensor probes, stated, for early detection near dishwashers, water heaters and washing machines. Two sets rather than one is a real difference — a single contact pair can sit above a shallow film of water that a second, differently placed pair catches | Local out of the box: the 105 dB alarm sounds where the detector is and nothing else happens. Remote monitoring exists only with the H5044 gateway bought separately, which puts this on the local side of the introduction's first distinction until you spend more |
| Aqara TZ-005 Water Leak Sensor, Zigbee, 3-pack | $55 | 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 | Highly sensitive probes on the body, with no wiring and no screws — placeable on any flat surface. No remote probe and no cable | 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 |
| eufy Security T8920 water and freeze sensor, HomeBase required | $35 | A SINGLE replaceable battery lasting up to 2 years, stated. Two years is the shortest of the four published lives on this shelf, and replaceable with one cell is the easiest maintenance on it: the five-year detectors here are sealed or take two AAA | Base contacts: place it anywhere you want to detect water. No probe and no cable, where one detector on this shelf supplies 5 ft of cable extendable to 500 | Remote only: instant notifications through the eufy Security app if water is detected or the temperature drops, with battery status visible. No siren of its own — the sound, if any, comes from the HomeBase |
Details checked on October 8, 2026.
Six awkward spots — behind a toilet, under a kick plate, in a drain pan — with no app and no account
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.
