Water leak sensors sit beside the appliances most likely to fail and alert you within seconds, long before a slow leak becomes a floor replacement.
Placement beats specification here. The highest-value spots are the washing machine, dishwasher, water heater and under sinks — the failure points that leak quietly and out of sight. A cheap sensor in the right place is worth more than an expensive one in the wrong one.
Two features are worth paying for: a local siren, so the alert works even if your network is down, and an optional cable probe, which extends detection along the length of a drip tray rather than a single point. If you want a system that acts rather than only notifies, look for sensors that pair with an automatic shut-off valve on the main.
