Either a dead battery or poor Wi-Fi signal can cause a Smart Wireless Soil Sensor to disconnect. If the Battery Level is still viable and the Signal Strength is not connected, take the sensor and go through the setup process (instructions can be found at How do I pair my Smart Wireless Soil Sensor? ) with the Smart Sprinkler Controller to reconnect it (instructions can be found at My soil sensor is not pairing, what do I do?). If the Signal Strength is viable and the Battery Level is low or dead, a replacement Smart Wireless Soil Sensor will be needed.
If none of these solutions resolve your disconnection issue, please access the Support page from the Settings page within the Smart Water Network application for additional assistance.