Water damage from a slow leak can go unnoticed for months — the Flo by Moen Smart Water Detector is a small, inexpensive sensor built specifically to catch that before it becomes a real problem, sitting quietly under a sink or water heater until it needs to alert you.
Check price on AmazonQuick specs
Wall-mounted base unit (AC powered, needs an outlet within about 10 ft) connects via 2.4GHz Wi-Fi directly to your home network — no separate hub required. The included 4-ft sensor cable ends in a puck you place at the leak-risk spot; longer 6-ft and 25-ft cables are sold separately and can be chained for more reach. Alerts arrive via the Moen Smart Water app, with optional text/call/email alerts through a paid FloProtect subscription (about $5/month). No Alexa, Google, or Matter integration.
Who it's designed for
Homeowners who want targeted early-warning coverage of specific leak-prone spots — under sinks, behind washing machines, near water heaters — rather than a whole-home shutoff system. Especially useful if you already own the larger Flo by Moen Smart Water Shutoff valve, since this detector can trigger it automatically.
Worth knowing
- There's no IFTTT support and no broader smart-home ecosystem integration — this is a standalone safety device, not a smart-home hub citizen
- Covering multiple leak-risk spots in a larger home adds up: roughly $50+ per additional unit, plus $20 for each extension cable if you need more reach
- Some users report occasional Wi-Fi pairing hiccups causing a unit to go "unsynced" and trigger nuisance alerts
How it compares
- Flo detector vs. a basic battery water alarm — the Flo costs more but gives you phone/text/email alerts instead of just a local beep, which matters if you're not home when a leak starts
- Flo detector vs. Flo Smart Water Shutoff (whole-home valve) — the detector is a cheaper, targeted option for specific risk spots; the shutoff valve is a bigger investment that can actually stop the water automatically
Bottom line
For the cost of a nice dinner out, this sensor can catch a leak under your water heater or sink months before it becomes a flooring-replacement problem — just budget for the optional FloProtect subscription if you want text/call alerts, not just app notifications.