Quick answer: put a Wi-Fi leak sensor beside the water heater and under each sink, and add a whole-home shutoff valve if you travel or own a rental. None of this replaces flood insurance.
Houston homeowners think about water from two directions. Outside, the Harris County Flood Control District says a major flood happens somewhere in the county about every two years [1], and Hurricane Harvey dropped 54 inches of rain near Bunker Hill Village between August 25 and 31, 2017 [2]. Inside, the threat is a slow leak in an attic water heater or air handler that no one sees for days. Leak sensors are built for the second problem. For the first, FEMA’s warning is plain: most homeowners policies don’t cover flood damage, and flood insurance typically takes 30 days to begin [3].
At a glance
- Major floods in Harris County
- About every two years, somewhere in the county [1]
- Harvey's highest Harris County total
- 54.00 inches near Bunker Hill Village, Aug. 25 to 31, 2017 [2]
- Flood insurance waiting period
- Typically 30 days [3]
- Homeowners policies and flood
- Most don't cover it [3]
- Dry wet materials within
- 24 to 48 hours to prevent mold in most cases [4]
How we chose
- Alerts that reach you away from home, by app, and on-device sound for when you’re there.
- Freeze or temperature alerts, because hard freezes do reach Houston: the state counted 43 deaths in Harris County from the February 2021 winter storm [10].
- Battery-powered sensors so they keep working when an outlet isn’t nearby.
- Specs from maker documents and a CPSC recall search for each brand and model on November 2, 2026 [9].
Our picks
Best for: Water heaters and laundry rooms
Moen Smart Leak Detector (920-004)
Senses water at the base or at a 48-inch remote disc you can slide under an appliance, and also tracks humidity and room temperature with alerts you set in the app.
- Wi-Fi, 2.4 GHz [5]
- 48-inch remote sensing disc included [5]
- Humidity and temperature alerts you can set [5]
- CR123A lithium battery, up to 2 years, included [5]
- Optional 6-foot sensing cable sold separately [5]
Safety check: FCC Part 15 compliant per Moen. No CPSC recall found for the leak detector (checked 2026-11-02).
Watch out: One-year warranty. It can only shut off your water if you also own Moen's Flo shutoff valve.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Attic air handlers and freeze-prone spots
Resideo (Honeywell Home) Wi-Fi Water Leak and Freeze Detector RCHW3610WF
Runs on AA batteries and connects straight to Wi-Fi, with low-temperature alerts and a jack for a cable sensor that turns the whole cable into a sensor along a drain pan or pipe run.
- Powered by 3 AA batteries, included [6]
- Cable sensor jack; the entire cable length senses water [6]
- Temperature and humidity alerts in the Resideo app [6]
Safety check: FCC Part 15 compliant per Resideo. No CPSC recall found for this detector (checked 2026-11-02).
Watch out: Resideo says it can take up to a minute to sense a leak, to save battery. Don't plug anything into the cable jack except the sensor cable.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Homes without reliable Wi-Fi near the water heater
Ring Alarm Flood and Freeze Sensor (2nd Gen)
Connects over Amazon Sidewalk rather than your Wi-Fi, so it doesn't need a Ring Alarm base station, and alerts when temperatures drop below 40°F.
- 2 AA batteries [7]
- Amazon Sidewalk, no base station required [7]
- Freeze alert below 40°F [7]
- Operating range 32°F to 120°F [7]
Safety check: No CPSC recall found for Ring flood and freeze sensors (checked 2026-11-02).
Watch out: Depends on Amazon Sidewalk coverage, which Ring says varies by location. The 32°F to 120°F operating range means a summer attic can exceed it.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Best for: Rentals, second homes and travelers
Moen Flo Smart Water Monitor and Shutoff, 1 inch (900-006)
Watches flow on the main line, runs a daily test that can catch a drip per minute, and shuts off the house's water automatically. Pairs with the Moen leak detectors above.
- Fits pipe 1 inch or smaller [8]
- Daily microleak test [8]
- Needs an outlet within 10 feet and 2.4 GHz Wi-Fi [8]
- No subscription required, per Moen [8]
Safety check: No CPSC recall found for the 900-006 valve itself. Moen recalled a separate Flo battery back-up accessory in 2023 for a fire hazard; check any back-up battery against that recall (checked 2026-11-02).
Watch out: Moen recommends a licensed plumber, which adds to the cost. It works on the house's supply line only, so it can't stop a backed-up drain or floodwater.
See it on Amazon → We chose it from specs and safety records; we haven't tested it ourselves.
Buying guide
- Start with the water heater. It’s the one appliance that can empty a full tank onto the floor. Then cover each sink, the washer and the AC drain pan.
- Pick by connection. Wi-Fi sensors need a 2.4 GHz signal where they sit. If your attic has none, look at a Sidewalk sensor or a cable sensor run to a better spot.
- Add a shutoff valve if a leak could run for days before anyone notices.
- Check flood insurance separately. Sensors won’t help with rising water, and a new flood policy usually isn’t active for 30 days [3].
Sources
- Harris County Flood Control District: Hurricane Harvey
- National Weather Service Houston/Galveston: Hurricane Harvey rainfall
- FEMA: flood insurance and homeowners coverage
- U.S. EPA: A Brief Guide to Mold, Moisture and Your Home
- Moen: Smart Leak Detector specification sheet (920-004, 920-005)
- Resideo: Wi-Fi Water Leak and Freeze Detector installation guide
- Ring: Flood and Freeze Sensor (2nd Gen) support page
- Moen: Flo Smart Water Monitor and Shutoff
- U.S. Consumer Product Safety Commission: Recalls database
- Texas Department of State Health Services: February 2021 Winter Storm-Related Deaths, Texas
Common questions
Will a leak sensor protect my house in a Houston flood?
No. A leak sensor tells you water is on the floor, which is most useful for a burst pipe, a failing water heater or an AC drain line. It can't keep floodwater out. For flooding, the protection is flood insurance, which FEMA says typically takes 30 days to start.
Where should I put water leak sensors?
Next to the water heater, under sinks, behind the washer and dishwasher, under the refrigerator's water line, and near the AC air handler's drain pan if it's in the attic or a closet.
Do I need a plumber for an automatic shutoff valve?
Moen recommends a licensed plumber for its Flo shutoff, which installs in line on your main cold water line after the meter and shutoff.