Best Way To Find A Water Leak Underground. Survey all valves and meters in the immediate area of the leak, using the headphones to listen and determine which valves are effected. A barefoot walk through your home is a good way to discover where you might have.
If it is, the leak is in your service line. That means turning off all faucets, washing machine and dishwasher, and ensuring that no electrical device using water is running. Give it about twenty minutes for water in the system to stop flowing.
This takes away the need to physically inspect each water pipe to find the leak.
If yes, you have a leak. This method is also one way that plumbers can find underground leaks. If it is, the leak is in your service line. While the sound might echo through pipes up to 1,000 feet from the source, the two valves with the loudest sound are likely on either side of the leaking pipe.