Pipes & leaks
How to Find a Hidden Water Leak
Updated · Kestrel editorial
Short answerTurn off all water, read the meter, wait an hour without using water, and read it again. Movement means a leak. Check toilets, the water heater, irrigation and the yard over the service line; if it's still hidden, professional leak detection pinpoints it.
Meter test
Many meters have a small leak indicator that spins with any flow.
Usual suspects
- Running toilets
- Water heater relief valve
- Irrigation valves
- Service line in the yard
- Hose bibs
Professional detection
Acoustic and thermal tools find leaks behind walls and underground. See leak detection.
What professional leak detection uses
Plumbers isolate sections of the system with pressure tests, then pinpoint leaks with acoustic listening equipment, thermal imaging and moisture meters, so any opening in walls or floors is as small as possible.
How to Find a Hidden Water Leak: follow-up questions
How do I check if I have a leak?
Turn off every fixture and appliance, then watch the water meter. If the leak indicator moves, water is escaping somewhere.
Can a leak hide under a basement slab?
Yes. Warm floor spots, damp carpet or unexplained high bills can point to a slab or under-floor leak.
Every home differs; editorial standards.