Automatic water leak detection and shut-off systems: whole-house valves, appliance-specific shut-offs, sensors and replacement parts.
These devices close the supply when a sensor detects water, which converts a burst supply line from a claim into an inconvenience. The two architectures are worth distinguishing. A whole-house valve mounts on the main and shuts everything, and the better ones also monitor flow patterns to catch a slow leak that never wets a sensor. An appliance shut-off protects one point — a water heater, a washing machine, an ice maker — and is far cheaper to fit.
Placement beats sensitivity. A sensor belongs at the lowest point where water would actually collect: under the tank, behind the machine, at the pan drain. Mounted an inch too high or on the wrong side of a floor slope, it reports nothing while the room floods.
Battery-powered units need a battery check on a schedule; hardwired units need to fail closed, not open, on power loss. Confirm which behavior a given model has.
Brands include Resideo, Moen and FloodStop.
