Before calling anyone out for a suspected leak, there's a simple test you can do yourself in about five minutes that tells you whether water is actively moving through your system when it shouldn't be.
How to Do It
- Make sure every water-using fixture and appliance in the house is off — faucets, toilets not mid-fill, ice makers, sprinkler systems, everything.
- Find your water meter, typically located near the curb in a small in-ground box, or sometimes at the side of the house.
- Note the current reading, or check for a leak indicator — many meters have a small triangular or star-shaped dial that spins with any water flow, however small.
- Wait 15 to 30 minutes without using any water, then check again.
Reading the Result
- Leak indicator not moving, reading unchanged: no active leak at the time of the test.
- Leak indicator moving, or reading changed: water is moving somewhere in the system. This doesn't tell you where, just that something is happening.
A Second Test to Narrow It Down
If the meter test shows movement, shutting off the main water valve to the house and checking whether the meter stops moving can help narrow down whether the leak is inside the home's plumbing or on the city side of the meter, which is generally the city's responsibility rather than yours.
What to Do With a Positive Result
A positive result doesn't tell you whether you're dealing with a running toilet flapper (cheap, easy fix) or a slab leak (a real repair). It just tells you it's worth having someone actually locate the source rather than ignoring it. The water bill is usually the other early indicator worth checking alongside this test — an unexplained increase points the same direction.