Hidden plumbing leaks are expensive because they often run quietly. The pump cycling pattern is one of your best clues.
Use the pump as a pressure monitor
With city water disconnected and all fixtures closed, repeated pump cycling means pressure is escaping somewhere.
Dry first, then inspect
Dry suspect areas completely. Press tissue around fittings, valves, filter housings, toilet valves and water-heater connections.
Look below and above
Water may drip from an enclosed belly far from the actual leak. Look uphill along plumbing and framing.
Isolate sections
Manifold valves, fixture shutoffs and bypasses can help divide the system. Change one valve at a time and record pump behavior.
Map moisture
A non-invasive moisture meter is useful when compared with known-dry areas. Watch trends, not one magic number.
Keep troubleshooting
Use these related RV Solver resources to narrow the problem and avoid parts guessing.
When to call a professional
Use professional leak testing for sealed bellies, soft floors, hidden walls, water near wiring or moisture that does not dry after repair.
Sources and editorial notes
RV Solver pages are written for practical owner education, then safety-edited for common electrical, propane, water, roof, appliance and towing risk points. Always confirm procedures with the manual for your exact RV and installed component. See our editorial policy.