It would’ve been a whole other story if they’d had water leak sensors.  They would’ve known there was a problem immediately and called to get the water turned off. No plane tickets required. An extreme example, but one of many reasons we think water leak sensors are a good idea—especially if you have a second residence you don’t visit very often. Water can ruin carpet pads, carpets, hardwood floors, upholstery, electrical appliances, antique furniture, important papers, favorite books, you name it. Even once you clean up a flood, mold can set in, and your home and possessions may never be the same. A water sensor is a good way to prevent all that. Yeah, it’s not surefire, but it’s better than no leak-detection system. Even if you rarely leave home, you may not immediately notice that leak under the sink, behind the washer, or in that one basement room that creeps you out a little. You never knew where hidden leaks might spring up; it takes one burst pipe or one backed-up sump pump to create a disaster. There are lots of different types of water leak sensors. Generally, the small portable sensors used for smart home and security systems detect moisture and/or temperature changes to determine if your pipes leak or freeze. We’re just not sure how they do it. For instance, some sensors find leaks by measuring water pressure, while others know water’s around because the drops complete an electrical circuit.¹ Because the sensors we’re thinking of usually sit under a pipe, we’re leaning more towards the circuit theory. But we don’t know for sure because home security providers aren’t sharing. (To be fair, this is a pretty obscure topic, and most users aren’t asking about it.) Some flood sensors are also freeze sensors—they ensure your pipes aren’t below a certain temperature. That may sound like a different kettle of fish, but since cold spells damage pipes, it goes hand in hand with water leaks. In fact, some systems use only freeze sensors to prevent potential leaks instead of sensing them after they occur. And some sell their freeze sensors and flood sensors separately. The main thing we recommend looking out for is installation type. Are you comfortable installing the sensor on your own? If you are, DIY should work just fine. If you’re not, you might want to consider a professional setup. If you have a separate freeze sensor, the process should be about the same.

Near refrigerators, tubs, and toiletsUnder sinks and other plumbing

Behind the water heater and washing machine

Why use a water leak sensor? It’s an easy, relatively inexpensive way to keep your home dry. How does a water leak sensor work? There are a few different ways a leak sensor might operate, but all of them work well for home needs. Which water leak sensor should I choose? It depends on if you also want a freeze sensor—and if you want to install it yourself. How do you install a water leak sensor? For most sensors, you just connect it and set it on the floor. How Can a Water Leak Sensor Save Your Home from Flooding  - 82