Step-by-step guide

Installing Sploosh

From unboxing to live leak detection in about 10 minutes.

In the box

  • Sploosh controller (ESP32-based, pre-flashed)
  • Water leak sensor (4 wire leads)
  • USB-C power cable
  • USB-C power adapter (5V, 1A minimum)
  • Quick-start card (Wi-Fi hotspot name, password, and HomeKit pairing code)

Part 1 — Sensor placement

1

Choose where to place the sensor leads

Sploosh requires USB-C power, so it needs to be within reach of a power outlet. The best locations are equipment rooms and utility areas where water heaters, HVAC units, and boilers are installed — these spots tend to have both outlet access and real leak risk.

Good locations include:

  • Next to a water heater or boiler
  • Near an HVAC air handler or condensate drain
  • Behind or under a washing machine
  • In a mechanical or utility room
⚡

Power outlet required

Sploosh connects over Wi-Fi and runs on USB-C power — no batteries, no Zigbee coordinator. Choose a location where a standard outlet is accessible to plug in the included USB-C adapter.

2

Connect the sensor leads to Sploosh

Plug the sensor's 4-pin connector into the matching port on the Sploosh controller. The connector is keyed — it only goes in one way.

Run the cable from the sensor leads to wherever you'll mount the Sploosh controller. The controller can sit on a shelf, be mounted to a wall, or rest nearby — it just needs to be within cable reach of the sensor and within Wi-Fi range.

3

Spread the sensor leads on the surface

Lay the four wire leads flat on the surface, spread apart so that any pooling water can bridge between two or more of them. The leads don't need to be perfectly arranged — just resting on the surface in the area where water would collect.

💡

Spread them out

The wider apart the leads, the larger the detection area. Even a small amount of water bridging any two leads is enough to trigger an alert.

Part 2 — Wi-Fi setup

4

Power on Sploosh

Connect the USB-C power adapter. Within a few seconds, Sploosh will broadcast a Wi-Fi hotspot.

Hotspot name sploosh
Hotspot password waterleak123

The two status LEDs will be off at startup (no water detected). They will light up if any two sensor leads are bridged by water.

On your phone, connect to the sploosh hotspot. A captive portal will open automatically — if it doesn't, open a browser and go to http://192.168.4.1 (or http://192.168.4.1:8080 for the HomeKit version).

5

Enter your home Wi-Fi credentials

On the configuration page, tap Configure and enter your home Wi-Fi network name and password. Sploosh only connects to 2.4 GHz networks.

You can also set a custom name for the device (e.g. "Water Heater" or "HVAC Room"). This is the name that will appear in Home Assistant or the Home app.

Save the settings. Sploosh will reboot and connect to your home network within 30 seconds.

Part 3 — Smart home connection

6

Connect Sploosh to your smart home

The next step depends on which version of Sploosh you have:

Add to Home Assistant

Sploosh uses ESPHome and is discovered automatically by Home Assistant on the same network.

  1. In Home Assistant, go to Settings → Devices & Services.
  2. Look for a new ESPHome device in the Discovered section. It will appear as sploosh-XXXXXX.
  3. Click Configure and follow the prompts to add it.
  4. The device exposes three entities: a Water Leak binary sensor, a Temperature sensor, and a Humidity sensor.
  5. Add these to your dashboard or use them in automations.

🔔

Set up a leak notification

In Home Assistant, go to Settings → Automations and create an automation that triggers when the Water Leak sensor state changes to Detected. Send a mobile notification, flash a light, or trigger a siren.

Pair with Apple HomeKit

Sploosh appears as a HomeKit accessory on your local network automatically after connecting to Wi-Fi.

  1. Open the Home app on your iPhone or iPad.
  2. Tap + → Add Accessory.
  3. When prompted, scan the QR code on your quick-start card — or tap More Options and enter the 8-digit pairing code printed on the card.
  4. Home app will find Sploosh. Name it and assign it to a room (e.g. "Utility Room", "Laundry Room").
  5. Sploosh exposes three accessories: Leak Sensor, Temperature Sensor, and Humidity Sensor.

🔔

Set up a leak notification

In the Home app, tap the Leak Sensor, then tap the settings icon. Enable Status and Notifications to get an alert on your iPhone whenever a leak is detected.

7

Calibrate temperature and humidity offsets (optional)

If the temperature or humidity readings seem slightly off due to heat from nearby equipment, you can apply a calibration offset.

  • Home Assistant: Go to Settings → Devices & Services → ESPHome, find the Sploosh device, click Configure, and adjust the Temperature offset and Humidity offset values.
  • HomeKit: Open a browser and go to http://sploosh.local:8080 (or the device's IP address with :8080). Scroll to the Calibration section, enter a temperature offset (°F) and humidity offset (%), and click Save Calibration. The values are stored on the device and survive reboots.

Part 4 — Test everything

8

Test water leak detection

Dampen a paper towel and briefly touch it across two or more of the sensor leads. Within a second or two, the two status LEDs should light up and the Water Leak entity should change to Detected.

Remove the moisture and the sensor should return to Clear within a few seconds.

9

Check temperature and humidity readings

Verify that the temperature and humidity readings look reasonable for the location. If not, apply a calibration offset as described in Step 7.

10

Test your notification automation

Trigger the sensor again with a damp paper towel and confirm that your notification fires — Home Assistant automation, HomeKit notification, or whatever action you configured.

Troubleshooting

Symptom Likely cause Fix
No "sploosh" Wi-Fi hotspot after power-on USB power insufficient or device not booting Try a different USB-C cable or adapter (needs 5V, 500mA minimum). Wait 30 seconds.
Captive portal page won't load Phone auto-switching back to mobile data Disable mobile data temporarily. Manually navigate to 192.168.4.1.
Sploosh doesn't appear in Home Assistant Not on same network, or HA discovery disabled Confirm Sploosh connected to Wi-Fi (check your router's device list). In HA go to Settings → Devices & Services and click Add Integration → ESPHome, then enter sploosh.local.
Sensor triggers without water present False positive from grounded metal contact The 3-sample debounce filter should prevent this. Reposition the sensor leads away from metal surfaces or grounded pipes.
Sensor doesn't trigger when wet Sensor leads not resting on surface, or connector loose Ensure the leads are spread flat on the surface and the 4-pin connector is fully seated. Test by touching a damp cloth across two leads directly.
Temperature reading seems high Controller heat or nearby heat source Apply a negative temperature offset in Home Assistant (Step 8). Move the controller away from heat sources if possible.
Need to change Wi-Fi network Moving router or changing network Factory reset Sploosh by power-cycling it 5 times within 10 seconds. It will return to hotspot mode for reconfiguration.
HomeKit shows device as "No Response" Sploosh offline or pairing lost Check your router's device list to confirm Sploosh is online. If it is, try removing and re-pairing the accessory in the Home app. If offline, power-cycle Sploosh and wait 30 seconds.
HomeKit pairing code not working Pairing window has closed or code mismatch Sploosh must be on your Wi-Fi network before pairing. Ensure setup is complete through Step 6 first. If the code still fails, factory reset and start over.