How it works
A leak sensor detects water reaching its sensing contacts or probe. It can then report an event through a compatible hub, network or built-in alarm, depending on the design. Common placements include likely collection points near appliances and plumbing. It monitors the place where it is positioned rather than every pipe or the entire room.
Important differences and limits
Detection of water is different from preventing a leak. Automatic shutoff requires a separate compatible valve and an intentionally configured control path. Battery condition, contact cleanliness, connectivity and the route to the notification recipient affect usefulness. A sensor can remain dry while water follows another path or pools somewhere else.
A useful practical check
Select a position using the actual floor shape and likely leakage route. Follow the manufacturer’s test procedure without exposing equipment to conditions it does not permit. Confirm local signalling, remote alerts and recovery after testing. Inspect battery and availability indicators, and ensure recipients know what location the sensor name describes.
An example in practice
For example, a sensor behind a washing machine may identify a small puddle before it becomes visible from the doorway. Check that water would actually reach the contacts and that the alert identifies that appliance clearly. If a shutoff is added, verify its separate operation and manual alternative; a received alert alone does not prove that water has been stopped.