I have a hot water heater. Many people do. It has a pressure release valve, which means it could release water onto the floor. That's why the manufacturer recommends putting a pan under it. As you can see, I went with a very large pan. Since the water heater is in the basement where I don't venture everyday, how will I know if water is flooding my basement?
Step 1: Make a Water Detector
I took a phone line coupler and put a neodymium magnet inside. Then I took two lengths of 14 gauge wire and pushed them thru. I put a piece of pink foam in between the wires to keep them separated and used glue to finish the assembly.
Step 2: Mount Your Detector
The magnet in the detector mounts to the inside of the tub. I used a paper clip to secure the wires to the top of the tub. Then I ran the wires thru the wall to upstairs.
Step 3: Connect to Doorbell
Luckily my door bell has a separate chime for front and back door. I have no back door bell so I connected my Leak Detector wires there. As long as water is making a connection at the detector, the chime will buzz. This can of course be used anywhere you expect you might have a leak or flooding in your house.