There are two main types of water leak detector: professionally installed models with a shutoff valve that is spliced right into your water line, and DIY models that sit on the quarter-turn valve on your water line and use a motor to open and close the valve automatically if a leak is detected.
We put five models to the test—three professionally installed systems and two DIY options. Ranging in price from $350 to $700, these systems are made by Flo by Moen, Guardian by Elexa, LeakSmart, Phyn, and StreamLabs. For the professionally installed systems, expect your cost to almost double when you factor in plumbing work. According to HomeAdvisor, it costs $375 to more than $600 to replace a main water-shutoff valve.
Below, you’ll find the details on the best professionally installed water leak detector system and the best DIY model from our tests. For the results of all the models, see our water leak detector system ratings.