There are a few different methods used to detect a leak. If it seems as though a leak has sprung somewhere in your system, the next step is finding its location. Using a variety of detection equipment, such as thermal leak detectors, is sometimes necessary for hard–to–find leaks. There are various approaches a plumber can take to discover a leak, whether it’s in the main water line or behind a wall. The first step, however, is knowing that you have a leak at all, and that’s largely the responsibility of the homeowner.