Water damage is the second leading cause of property damage, and about one in 60 insured homes files a claim due to water or freezing damage each year. Smart water-leak detectors are one way to discover a water-leak issue before it becomes a disaster. These puck-like devices can detect pooling water, trigger an alarm, and send you a smartphone notification.The YoLink Water Leak Sensor 4 is the best smart water-leak detector we tested, due to its quick response time, effective alarm, and easy setup.