This little magical wireless device unit it's a combination of flood, low temp, and high temp combination. wherever you want to monitor the possible water leakage you can monitor the low and temp as well. Wherever there is water pipe there is a chance of a water leak. next to water heater, under the kitchen sink, laundry room, and sump pump. you can put Water leak devices for early detection before it's too late. Those little pins when are submerged in water for over 20 seconds go into alarm and notify you through the monitoring station that there is a leak so you can attend to the problem as quickly as possible before the whole house is ruined. Small investment goes a long way.
And there is the hardwired version of the same device except it does not come with low and high temperature sensors. They have to be added if interested.