Start with the bill, not the leak theory
Compare water use
Find the gallons or other usage unit for this period. Compare it with the previous period and the same season last year. Guests, lawn watering, a new appliance, extra cleaning, or a change in routine can raise real use without a leak.
Compare the charges
Check the number of service days, whether the reading was actual or estimated, and whether rates, wastewater charges, credits, or prior balances changed. The dollar total can rise even when measured use stays steady.
Check for a utility notice
A meter exchange, corrected reading, account adjustment, or unusually long cycle belongs in the billing conversation. Ask the utility to explain an unfamiliar line item rather than treating it as a plumbing diagnosis.
If water use increased, check the likely sources
- Listen for a toilet that refills between uses, then use a tank dye test if the fixture and tank are safe to access. EPA recommends observing whether dye moves from the tank into the bowl without flushing. [1]
- Look beneath sinks and around water heaters, washing machines, dishwashers, refrigerators, hose connections, and irrigation controls. Damp cabinets and slow connection leaks may never create an obvious puddle.
- Choose a period when no one will use water. Confirm that toilets, irrigation, washing machines, dishwashers, water softeners, ice makers, humidifiers, and other automatic equipment are idle. Record the meter, wait, and compare it again. [1]
- If the meter changes, close fixture or equipment shutoffs one at a time only when they operate normally. A change after isolating one branch can narrow the search without opening walls.
Patterns that point in different directions
| Pattern | A useful next check |
|---|---|
| Usage rises only in watering months | Review irrigation schedules, stuck valves, overspray, hoses, and outdoor connections. |
| Meter changes all day and night | Look for continuous fixture flow, an appliance connection, a service-line leak, or a concealed supply leak. |
| Meter moves in short bursts | Watch for toilets refilling or automatic equipment cycling. |
| Dollar total rises but usage is steady | Ask the utility about rate, cycle, estimate, wastewater, balance, and adjustment details. |
| A room is damp or a floor area changes temperature | Stop relying on the bill and arrange location-specific moisture and leak evaluation. |
A whole-home flow monitor can learn or compare patterns, notify the user, and in some configurations close a valve. A point sensor detects water only where the sensor is placed. Neither type identifies every source or replaces inspection of the affected area. EPA advises choosing devices around the intended location, pipe compatibility, alert method, shutoff behavior, power and connectivity needs, and ongoing maintenance. [3]
If the extra use remains unexplained, share the high-usage dates, meter observations, irrigation schedule, recent occupancy changes, and any rooms where moisture appeared. Those details help separate a fixture that runs repeatedly from an underground or concealed supply leak.