Water Leak Sensors · Head to head

Shelly Flood vs Third Reality Water Leak Sensor

Full Smart Water Leak Sensors comparison in 2026

Updated October 2026
Data from Amazon and official Shelly and Third Reality sites.
2026 verdict
A siren you can hear from the next room and a lower price put the Third Reality Water Leak Sensor ahead of the Shelly Flood.
Third Reality Water Leak Sensor
Winner
Third Reality Water Leak Sensor
$20.99

Last recorded price

Buy on Amazon USA
It sounds a 120 dB alarm, runs about three years on two AAA cells with low-battery alerts, and pairs over Zigbee with SmartThings and Home Assistant, reaching Google Home and Apple Home through a Smart Bridge MZ1. The Shelly Flood answers with a temperature sensor and freeze alerts the Third Reality lacks, joins 2.4 GHz Wi-Fi with no hub, and carries a two-year warranty against one. Pick the Third Reality for a Zigbee home that wants a loud, long-lasting alarm, the Shelly for freeze warnings and a Wi-Fi sensor with no hub to buy.
Shelly Flood
Shelly

Shelly Flood

Prime exclusive deal
Lowest price of the last 6 months
10% above its lowest price of the last 6 months (€23.90)

Last recorded priceFeb 6, 2026$24.99

Currently unavailable on Amazon USA
See on Amazon USA
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FeatureShelly FloodThird Reality Water Leak SensorWinner
Rating3.84.1Third Reality Water Leak Sensor
Warranty2 years1 yearShelly Flood
Battery Life1.5 years3 yearsThird Reality Water Leak Sensor
IntegrationsGoogle Home, Samsung SmartThings, Home AssistantGoogle Home, Apple HomeKit, Samsung SmartThings, Home AssistantThird Reality Water Leak Sensor
SensorsWater Leak, TemperatureWater LeakShelly Flood
AlertsWater Leak Alerts, Temperature Alerts, Freeze Temperature Alerts, Low Battery AlertsWater Leak Alerts, Low Battery AlertsShelly Flood
On Device Alert SoundNOYESThird Reality Water Leak Sensor
Connectivity2.4 GHz WiFiZigbeeTie
On Device Alert LightNONOTie

What the differences mean

Sensing

The Shelly Flood reads temperature and sends freeze alerts, while the Third Reality Water Leak Sensor detects water only. For a pipe that might freeze, the Shelly is doing a second job the Third Reality does not.

On-device alarm

The Third Reality Water Leak Sensor sounds a 120 dB alarm, while the Shelly Flood has no on-device sound or light. If you want a warning in the room with the leak, only the Third Reality delivers it.

Battery

The Third Reality Water Leak Sensor is rated for about three years on two AAA cells, while the Shelly Flood runs about 1.5 years on a CR123A that is not included. The Third Reality lasts longer and comes with its cells.

Connection

The Shelly Flood joins 2.4 GHz Wi-Fi with no hub, while the Third Reality Water Leak Sensor needs a Zigbee hub. If you would rather not add a hub, that is the Shelly's clearest advantage.

Warranty

The Shelly Flood carries a two-year warranty against one year on the Third Reality Water Leak Sensor. For a device left out of sight under a floor, the longer cover favors the Shelly.

Price and rating

The Third Reality Water Leak Sensor is the cheaper of the two and the better rated, while the Shelly Flood brings the freeze alerts and the hub-free Wi-Fi link. Budget and features point in different directions.

Which one to buy if

Shelly

Shelly Flood

Prime exclusive deal

Last recorded priceFeb 6, 2026$24.99

Currently unavailable on Amazon USA
See on Amazon USA
  • + Warranty: 2 years
  • + Sensors: Water Leak, Temperature
  • + Alerts: Water Leak Alerts, Temperature Alerts, Freeze Temperature Alerts, Low Battery Alerts
  • - Rating: 3.8 vs 4.1
  • - Battery Life: 1.5 years vs 3 years
Winner
Third Reality

Third Reality Water Leak Sensor

Prime exclusive deal
$20.99

Last recorded price

Buy on Amazon USA
  • + Rating: 4.1
  • + Battery Life: 3 years
  • + Integrations: Google Home, Apple HomeKit, Samsung SmartThings, Home Assistant
  • - Warranty: 1 year vs 2 years
  • - Sensors: Water Leak vs Water Leak, Temperature

What owners say

Owners of both sensors report a leak caught early and a device that keeps working once paired, and both groups value the local alert. Third Reality Water Leak Sensor owners praise the 120 dB alarm they can hear from another floor, the fast pairing with Home Assistant and Hubitat and the value that lets them cover a whole house, though a few mention raised sensing screws needing spacers for shallow water and occasional battery or connectivity trouble after a year. Shelly Flood owners like the no-app browser setup, the automatic pickup in Home Assistant and the combined leak and temperature data, but warn that some units drop off Wi-Fi and need manual reconnecting.

Price history compared

Every price change of both, in the same store, so the gap between the two lines is what one costs more than the other.

  • Shelly Flood
  • Third Reality Water Leak Sensor

Loading price history...

Frequently Asked Questions

Which is better overall: Shelly Flood or Third Reality Water Leak Sensor?

The Third Reality Water Leak Sensor, on price, a 120 dB alarm, battery life and low-battery alerts. The Shelly Flood is the better pick when you want freeze alerts and a Wi-Fi sensor that needs no hub.

What is the biggest difference between the Shelly Flood and the Third Reality Water Leak Sensor?

Sensing and alerting. The Shelly Flood reads temperature and sends freeze alerts but has no local alarm, while the Third Reality Water Leak Sensor sounds a 120 dB siren but detects water only.

Does the Shelly Flood need a hub, and does the Third Reality Water Leak Sensor?

The Shelly Flood joins 2.4 GHz Wi-Fi with no hub, while the Third Reality Water Leak Sensor needs a Zigbee hub such as SmartThings or Home Assistant. The Third Reality reaches Google Home and Apple Home only through a Smart Bridge MZ1.

Does the Third Reality Water Leak Sensor detect temperature or freezing?

No. The Third Reality Water Leak Sensor detects water only, with no temperature sensor or freeze alerts. The Shelly Flood reads temperature and sends freeze alerts for pipes in cold spaces.

Who should buy the Shelly Flood, and who should buy the Third Reality Water Leak Sensor?

Buy the Shelly Flood for a Wi-Fi home that wants leak and temperature sensing with no hub and a longer warranty. Buy the Third Reality Water Leak Sensor for a Zigbee home that wants a loud, affordable alarm and long battery life.

Full comparison table

Compare all 34 Water Leak Sensors side by side

You are looking at two of them. The full table lines up all Water Leak Sensors in the catalog with the same specs, so you can filter by what you need and sort by price or rating.

  • 34 Water Leak Sensors
  • 36 specs compared
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