Slab leak test: check your water meter in 15 minutes
Turn off every fixture and appliance, then read your water meter with the main house shutoff open, then closed. Answer what you found below for a verdict and a next step.
Answer these
Your result
no leak detected
Severity
monitor
Next step
No active leak showed up on this test; recheck if you notice warm floor spots, a higher bill, or the sound of running water.
This tool is a guide, not a diagnosis. It never asks you to open a slab, cut pipe, or touch gas or electrical. Confirm any leak with a licensed plumber.
Assumptions
- •This tool gives a diagnostic read, not a cost estimate; see the repair method finder and cost calculator for next steps.
- •Readings assume a standard residential water meter with a visible dial or digital readout.
Questions this tool answers
What if I do not have a leak indicator on my meter
Most residential meters have a small triangular or star-shaped dial that spins with any flow. If yours does not, choose "no leak indicator" and rely on the meter reading delta instead: any movement over 30 minutes with everything off means water is flowing somewhere.
Why does the test need the house shutoff valve, not just the meter
Closing the main shutoff valve at your house isolates your interior plumbing from the service line between the street and your meter. If the meter still moves with that valve closed, the leak is upstream of your home, not under your slab.
Can I do anything else myself before calling a plumber
You can retest to rule out a fixture you missed, and you can note where the floor feels warm to help a plumber locate a hot-line leak faster. Opening the slab or working on gas or electrical lines is not a DIY step.
How accurate is a 30 minute meter test
A 30 minute test with everything off is the standard first check plumbers use themselves. It reliably flags whether water is moving somewhere it should not, though it cannot tell you exactly where the leak is without electronic detection equipment.