Start with control points
Locate and label the main water shutoff, appliance valves, and building-management contact. Confirm who is authorized to operate them and whether a tool is required. A household plan should explain what to do if the valve is stuck, inaccessible, shared, or close to electrical hazards.
Inspect high-consequence locations
Check beneath sinks, around toilets, behind accessible appliance connections, near water heaters, under roof penetrations, and around known drainage points. Look for corrosion, staining, soft material, mineral deposits, musty odor, repeated condensation, or sound when no fixture is used. Do not disturb suspected asbestos or hidden electrical areas.
Use meters and sensors as clues
A water meter that moves during a controlled no-use period can suggest leakage, but irrigation, ice makers, treatment equipment, and shared supply can complicate the test. Sensors should be placed where water is likely to arrive and where alerts are heard or forwarded. Test batteries and notifications on a schedule.
Respond according to scale and safety
For an active leak, protect people first, avoid electrical contact, stop water only if safe and authorized, and contact the responsible professional or building manager. Photograph conditions and record actions. After repair, dry affected materials promptly and verify that moisture does not remain hidden.
An alert is useful only when someone can act
Know the shutoff, monitor likely failure points, test the notification path, and define who responds at home and away.
Further reading: EPA WaterSense leak information. External references are provided for context and do not imply affiliation.