Shelly
Shelly Flood Gen4
- Zigbee
- Wi-Fi
- Matter
- Bluetooth
Verified July 2026
The most flexible flood sensor Shelly's made — pick Wi-Fi, Zigbee, Bluetooth or Matter at setup and it joins whatever mesh you're already running, with a 2m cable extendable to 150m if you need to reach under a tank or behind a washing machine. Fully local through Home Assistant's built-in Shelly integration, no cloud, no subscription — just commit to one radio at pairing, since you can't run it on several at once.
In Home Assistant
| Control | Type | What it does |
|---|---|---|
| Leak | Binary sensor | Detects water contact along the sensor cable; 'wet' when moisture is present |
| Cable unplugged | Binary sensor | Diagnostic entity flagging a disconnected leak sensor cable (HA 2025.10.0+; requires a device re-add on existing installs) |
| Battery | Sensor (%) | Remaining battery percentage |
Uses HA's built-in Shelly integration over local RPC (HTTP/WebSocket via Gen2+ protocol), auto-discovered by mDNS — no cloud account needed. Support for Flood Gen4 was merged into HA core via PR #136981; a separate 'cable unplugged' diagnostic binary_sensor landed later in HA 2025.10.0, so if you're updating from an older HA version you'll need to remove and re-add the device for that entity to show up. As a battery device, wake it with its button before pairing. A useful automation: trigger a push notification and close a smart water shut-off valve (e.g. via a Shelly relay) the moment the leak binary_sensor goes 'on'.
Specs
- battery
- 4x AA 1.5V (included)
- ip rating
- IP44
- dimensions
- 97 x 76 x 25 mm
- battery life
- manufacturer claims approx. 2 years
- cable length
- 2m, extendable up to 150m via additional cables
- connectivity
- Wi-Fi 802.11b/g/n/ax, Bluetooth 5 LE, Zigbee 3.0, Matter over Wi-Fi (select one mode at setup)
- detection modes
- Flood and rain detection, 3 alarm sensitivities (Intense, Normal, Economic)
- operating temperature
- -20°C to 40°C