Shelly Flood S Gen4 Large Surface Smart Flood Sensor Setup Guide

Shelly Flood S Gen4 Large Surface Smart Flood Sensor - Setup Guide

Tools required:

  • 2x AAA batteries (typically supplied in the box)
  • A small flat-head screwdriver or coin (to open the battery compartment, if required)
  • A clean, dry cloth to wipe down the intended placement surface
  • A smartphone or tablet

Applications required:

  • Shelly Smart Control app (available for iOS and Android)
  • A Shelly Cloud account (free to create within the app)
  • Optional: Amazon Alexa app or Google Home app for voice assistant integration

Before you begin:

  • Ensure you have a 2.4GHz WiFi network available, along with the network name (SSID) and password. The Shelly Flood S Gen4 does not connect to 5GHz networks.
  • Confirm the ambient temperature at the installation location is between 0°C and 40°C.
  • Identify the placement area, for example under a sink, beside a washing machine, in a utility room, bathroom or basement. The surface should be flat so that the underside sensing contacts sit directly against it.

Step 1 - Install the batteries:

  • Open the battery compartment on the underside of the sensor using a coin or small screwdriver if a locking tab is present.
  • Insert the 2x AAA batteries, observing the correct polarity (+ / -) as marked inside the compartment.
  • Close the compartment securely. The device will power on automatically and enter pairing mode on first use, typically indicated by an LED flashing.

Step 2 - Install the Shelly Smart Control app:

  • On your smartphone, open the App Store (iOS) or Google Play Store (Android).
  • Search for Shelly Smart Control and install the app.
  • Open the app and either sign in to your existing Shelly Cloud account or register a new account using your email address.
  • Grant the app the permissions it requests, including Bluetooth, Location and Local Network access. These are required for device discovery and initial configuration.

Step 3 - Add the Flood S Gen4 to the app:

  • In the app, select your desired room or create a new one (for example Kitchen, Bathroom, Utility Room or Basement).
  • Tap the option to add a new device.
  • Follow the on-screen prompts to allow Bluetooth-assisted discovery. Keep your phone within a metre of the sensor during pairing.
  • When the Flood S Gen4 appears in the discovered devices list, select it.

Step 4 - Connect to WiFi:

  • Choose your 2.4GHz WiFi network from the list presented in the app.
  • Enter the WiFi password carefully and confirm.
  • Wait for the sensor to complete the connection process. The app will confirm when the device is online.
  • If prompted, allow the app to install any available firmware updates before continuing.

Step 5 - Configure notifications and settings:

  • Open the device page for the Flood S Gen4 within the app.
  • Assign a clear name, for example Under Kitchen Sink or Washing Machine.
  • Enable push notifications so that alerts are delivered to your phone the moment water is detected.
  • Optionally configure email alerts and, if desired, scenes or automations that trigger other Shelly devices when a leak is detected.

Step 6 - Position the sensor:

  • Wipe the chosen surface with a dry cloth to remove dust and moisture.
  • Place the sensor flat on the surface so that the water-sensing contacts on the underside are in direct contact with the floor or tray.
  • Ensure the location is level and stable, and that the sensor will not be knocked or moved during normal use.
  • Avoid installing the device where it may be fully submerged. The housing is water resistant, not fully waterproof.

Step 7 - Test the sensor:

  • Using a small amount of water on a fingertip or a damp cloth, briefly bridge the sensing contacts on the underside of the device.
  • Confirm that the sensor sounds its local alert and that a notification is received on your smartphone.
  • Dry the sensor thoroughly with a clean cloth and return it to its intended position.

Step 8 - Optional voice assistant integration:

  • Amazon Alexa: Open the Alexa app, go to Skills & Games, search for the Shelly skill, enable it, sign in with your Shelly Cloud credentials, and discover devices.
  • Google Home: Open the Google Home app, tap Add, choose Works with Google, search for Shelly, sign in with your Shelly Cloud credentials, and assign the sensor to a room.

Ongoing use:

  • Battery level is reported within the Shelly Smart Control app. Replace the AAA batteries when the app indicates a low charge.
  • Periodically test the sensor to confirm continued operation.
  • Check for firmware updates within the app to keep the device secure and up to date.

Note: The Shelly Flood S Gen4 is a battery-powered sensor and does not require any mains wiring. No electrical installation work is needed for this product.