Start with a no-use meter test when water use rises without an obvious reason. It can show that water is flowing somewhere, but it cannot tell you which pipe is leaking. Check toilets, irrigation and appliances before assuming the problem is inside a wall or in a buried line.
A dry house does not rule out a leak, and a higher bill does not prove you need water line repair. Record the meter readings and visible clues so a plumber can narrow down the source.
What should you check first?
Look at accessible fittings under sinks, appliance supply hoses, outdoor faucets and irrigation. Clark Public Utilities' leak checklist also names standing water and unexpectedly green or soggy lawn patches as possible outdoor clues. Follow the provider shown on your water bill when checking its meter.
How do you run a no-use meter test?
- Stop all water use, including irrigation and appliances. Make sure a toilet is not still refilling.
- Record the meter reading or photograph the accessible display. Note the time.
- Keep the water off for the test period, then compare the readings.
EPA WaterSense recommends checking before and after two hours with no water use. Clark Public Utilities describes a shorter, 15-minute sweep-arm check. Use your provider's instructions; a changing reading indicates unexplained flow, not the location or repair required.
How do you check a quiet toilet leak?
Add a few drops of food coloring to the tank without flushing. EPA says color reaching the bowl after 10 minutes indicates a leak. Flush immediately after the test to avoid staining. A toilet can waste water quietly, so check it even if you hear no running water.
What should you tell the plumber?
Share the two meter readings, elapsed time, which fixtures were off, and any wet areas. Mention whether irrigation or an appliance could have run during the test. Ask what the inspection establishes before approving a repair or excavation.
What should you tell the plumber
If materials are wet, address the water source and drying promptly. EPA's mold cleanup guidance emphasizes fixing the water problem. A damp spot alone cannot establish how much hidden damage exists or what a repair will cost.
Common questions about hidden leaks
Does a moving water meter mean I have a hidden leak?
It means water is flowing through the meter. First rule out a running toilet, irrigation or an appliance using water. If the reading keeps changing during a no-use test, a leak is likely; the meter does not identify its location.
Common questions about hidden leaks
How long should I wait between meter readings?
EPA recommends a two-hour period with no water use. Clark Public Utilities also describes a 15-minute sweep-arm check. Follow your water provider's instructions and repeat an inconclusive test before deciding on a repair.
How can I check a toilet that does not sound like it is running?
Place a few drops of food coloring in the tank without flushing. EPA says color appearing in the bowl after 10 minutes indicates a leak. Flush immediately afterward to avoid staining.
Could the leak be outside even if my house is dry?
Yes. Clark Public Utilities lists standing water and unusually green or soggy patches in a lawn as possible outdoor clues. Check irrigation and outdoor fittings too; a higher bill alone does not prove a buried service-line leak.
Should I replace a water line based on the meter test?
Use the test to guide further diagnosis. Ask the plumber to identify the leaking section and explain why a repair or replacement fits the findings before approving the work.
For active water damage, see the steps for handling a plumbing emergency. Repeated repair problems may also warrant a separate discussion about when to consider repiping.
True Plumbing offers leak detection and repair. Call (360) 207-6064 to describe the problem and confirm availability.
Sources and update notes
Last updated September 30, 2026. These primary and local references support the general guidance; your building, equipment, and utility can change the right repair.
- EPA WaterSense: leak checks and toilet dye test
- Clark Public Utilities: Find Your Water Leak checklist
- EPA: Mold Cleanup in Your Home
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