(2) Glentronics Watchdog BWD-HWA Water Sensor Alarm & (2) 9V Batteries

I use this alarm under any sink with a cabinet where a leak would not be noticed. This alarm sounds a very loud alarm the minute any water comes near it. No floating kitchen floors.

No need to spend more than this on all those other alarms. This works just fine and the alarm is loud enough to alert you even if you are upstairs!

Simple to use and very effective at detecting water .

I've got a few of these in my house and highly recommended them. I have two near our furnace and twice they've helped alert me to a drain hose becoming detached. It's loud enough that I can hear it several rooms away on another floor of the house. These helped me find and fix the problem before there was any water damage. The batteries last a long time.

We have several aquariums with filters inside the cabinet under the tanks. Even though rare, sometimes the filters or the plumbing to them leaks. If we don't notice the leak soon enough it's a real pain to clean up. Installed these alarms on the floor behind the aquarium where the water first goes if there is any leak. They saved us from damage to furniture and rugs once already, you can't help notice the blaring siren that they give off. In fact we didn't realize what it was at first and ran around the house trying to figure it out. Found the leak and stopped it before major damage occurred. These alarms are worth every penny.

This alarm works perfectly if you have a leaking HVAC unit! The alarm is simple and works really well

These things make a loud, high-pitched screeeeeeeing sound when moisture reaches the electrodes on the bottom. They have worked for me in the past with a notable exception when the battery had apparently died before my water heater began leaking. I now use a Sharpie to write the battery-change dates on the top of these units.Very good value.

Works great! Very loud!