Why does my Shelly Flood Gen4 trigger false flood alarms?

Modified on Wed, 1 Jul at 4:28 PM


False flood alarms are usually caused by the installation conditions of the sensor cable.


  • Metal surfaces: If the cable is installed directly on a metal surface, it may detect false signals.
  • Condensation: Moisture or condensation on the surface can mimic the presence of water and trigger an alarm.
  • Cable crossing itself: Ensure the sensor cable does not cross over or touch itself, as this can lead to false detections.
  • State hold time: Verify that the state hold time settings are configured appropriately.

Recommendation:

  • Do not install the sensor cable directly on metal. If installation on metal is necessary, place an insulating layer (such as tape, plastic, or another non-conductive material) between the surface and the cable to prevent condensation from causing false alarms.
  • Route the sensor cable so that it does not cross over or touch itself. Keep the cable laid out in a single path with adequate spacing between sections whenever possible.