Short answerCommon signs of a hidden water leak are a water meter that moves when all fixtures are off, an unexplained rise in your water bill, musty odors, stains or bubbling paint, warped floors, and the sound of running water. A meter test confirms a supply leak in minutes.
The five-minute meter test
- Turn off every faucet, toilet, appliance and irrigation system.
- Find the water meter (often in a box near the street, or in a basement in cold climates).
- Watch the low-flow indicator, a small triangle or dial. If it moves, water is flowing somewhere.
- For slow leaks, write down the reading, avoid using water for an hour or two, then check again.
- Close the house shutoff and recheck. If the meter still moves, the leak is in the service line outside.
Why acting early matters
Slow leaks feed mold, rot subfloors and framing, and in some soils contribute to foundation problems. Early detection keeps the repair small.
Frequently asked questions
How much does a hidden leak raise the water bill?
It depends on the leak rate. A running toilet or a pressurized supply leak can raise bills substantially; compare against the same month last year.
Can a leak be detected without opening walls?
Usually. Acoustic, thermal and pressure methods narrow it down so only a small opening is needed.
