Water Leak Sensors · Head to head

Heiman Smart Water Leakage Sensor vs Shelly Flood Gen4

Full Smart Water Leak Sensors comparison in 2026

Updated October 2026
Data from Amazon and official Heiman and Shelly sites.
2026 verdict
Where the Shelly Flood Gen4 pulls ahead of the Heiman Smart Water Leakage Sensor is what happens once the alarm is raised.
Shelly Flood Gen4
Winner
Shelly Flood Gen4
$39.99
Buy on Amazon USA
It supports Wi-Fi, Zigbee, Bluetooth and Matter, pairs with Apple Home and SmartThings through Matter plus Google Home and Home Assistant, and ships a 2 m sensing cable with a three-year warranty. It also adds temperature and freeze alerts and a local buzzer and LED. The Heiman Smart Water Leakage Sensor wins on price, on the tougher IP67 housing against IP44 and on battery life, five years on a CR123A against two on the Shelly, and it sounds a 75 dB alarm with an LED on its own. Its smart features need a separate Heiman gateway. Pick the Shelly Flood Gen4 for a connected, multi-protocol install, and the Heiman Smart Water Leakage Sensor for a cheap, stand-alone, long-life alarm.
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FeatureHeiman Smart Water Leakage SensorShelly Flood Gen4Winner
Price$16.99$39.99Heiman Smart Water Leakage Sensor
Rating4.24.1Heiman Smart Water Leakage Sensor
Warranty1 year3 yearsShelly Flood Gen4
Weather ResistanceIP67IP44Heiman Smart Water Leakage Sensor
Battery Life10 years2 yearsHeiman Smart Water Leakage Sensor
ConnectivityOther2.4 GHz WiFi, Bluetooth, ZigbeeShelly Flood Gen4
IntegrationsNoneGoogle Home, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterShelly Flood Gen4
AlertsWater Leak Alerts, Freeze Temperature Alerts, Low Battery AlertsWater Leak Alerts, Temperature Alerts, Freeze Temperature Alerts, Low Battery AlertsShelly Flood Gen4
SensorsWater Leak, TemperatureWater Leak, TemperatureTie
On Device Alert SoundYESYESTie
On Device Alert LightYESYESTie

What the differences mean

Protocols

The Shelly Flood Gen4 supports Wi-Fi, Zigbee, Bluetooth and Matter, so it can join almost any ecosystem. The Heiman Smart Water Leakage Sensor joins 2.4 GHz Wi-Fi and has no Zigbee, Z-Wave, Bluetooth or Matter radio.

Integrations

The Shelly Flood Gen4 reaches Apple Home and SmartThings through Matter, plus Google Home and Home Assistant. The Heiman Smart Water Leakage Sensor supports Home Assistant, has only partial SmartThings support and offers no Apple Home, Alexa or Google Home path.

Sensing

The Shelly Flood Gen4 includes a temperature sensor and raises both temperature and freeze alerts, so it can warn about a pipe at risk. The Heiman Smart Water Leakage Sensor detects water only, with no temperature or freeze channel.

Battery

The Heiman Smart Water Leakage Sensor is rated for five years on a CR123A, more than double the two years of the Shelly Flood Gen4 on four AA cells. On a sensor placed and forgotten, that is the Heiman's clearest advantage.

Sealing

The Heiman Smart Water Leakage Sensor is IP67, good for a damp utility corner or a spot that gets splashed. The Shelly Flood Gen4 is IP44, splash resistant but the less protected of the two in a wet space.

Warranty

The Shelly Flood Gen4 carries a three-year warranty against one year for the Heiman Smart Water Leakage Sensor. For a permanent install, that difference is worth as much as the price gap on day one.

Which one to buy if

Winner
Shelly

Shelly Flood Gen4

Prime exclusive deal
$39.99
Buy on Amazon USA
  • + Warranty: 3 years
  • + Connectivity: 2.4 GHz WiFi, Bluetooth, Zigbee
  • + Integrations: Google Home, Apple HomeKit, Samsung SmartThings, Home Assistant, Matter
  • - Price: $39.99 vs $16.99
  • - Rating: 4.1 vs 4.2

What owners say

Owners of both devices like a small puck that sits under a sink or behind a washing machine and sounds an alarm the moment water arrives. Heiman Smart Water Leakage Sensor owners value that it works with no app, no hub and no setup beyond dropping in the battery, and they call the 75 dB alarm loud enough to notice on its own. Their repeated complaint is the gateway: several bought a single sensor expecting remote alerts and found those need separate Heiman hardware that was not in the box. Shelly Flood Gen4 owners instead describe quick, stable pairing over Zigbee in Home Assistant and a cable sensitive enough to catch one drop, with their friction on Wi-Fi onboarding and an occasional Matter and HomeKit status that needed a button press.

Frequently Asked Questions

Which is better overall: the Heiman Smart Water Leakage Sensor or the Shelly Flood Gen4?

The Shelly Flood Gen4, for a connected home. It supports four protocols, adds temperature and freeze alerts and carries a three-year warranty. The Heiman Smart Water Leakage Sensor is the better stand-alone alarm, cheaper, better sealed and longer on a battery.

What is the biggest difference between the Heiman Smart Water Leakage Sensor and the Shelly Flood Gen4?

Whether they need the cloud to be smart. The Heiman Smart Water Leakage Sensor alarms on its own but needs a separate gateway for app alerts, while the Shelly Flood Gen4 joins your network directly and reports through the hub you choose.

Does the Heiman Smart Water Leakage Sensor need a gateway?

Not for its local alarm, which works immediately. Remote app alerts and the other smart features do require a Heiman gateway, and it is not bundled with every listing, so check before buying.

Which one works with Apple Home or Matter?

The Shelly Flood Gen4 does, reaching Apple Home and SmartThings through Matter. The Heiman Smart Water Leakage Sensor has no Apple Home, Matter, Alexa or Google Home support.

Who should buy the Heiman Smart Water Leakage Sensor?

A buyer who wants a loud, IP67, five-year stand-alone alarm under a sink or beside an appliance and does not need remote notifications.

Who should buy the Shelly Flood Gen4?

A Home Assistant, Matter or Zigbee home that wants one sensor to speak to almost anything, with a local buzzer and LED and a three-year warranty.

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