Your meter’s still moving with everything off? Then something’s leaking. Call or send a few details, and a local slab leak plumber will get back to you about finding it.
Find the meter
It’s usually in a box in the ground near the street or the front curb, with a lid you can pry up with a screwdriver. Watch for spiders and wasps. Some lids have a smaller flap over the dial itself.
Shut everything off
Turn off every faucet and shower. Make sure the dishwasher, washing machine, ice maker, and sprinklers aren’t running. Don’t flush anything. If you have a water softener, check that it isn’t in a regeneration cycle.
Watch the dial
Most meters have a small leak indicator on the face: a little triangle, star, or wheel that spins with even a tiny flow. If it’s turning, water is going through the meter. If your meter doesn’t have one, write down the reading, wait 30 minutes to an hour without using any water, and check again.
Some cities also let you see your usage online, hour by hour. If yours does, an hourly reading that never drops to zero overnight is the same signal.
It’s moving. Now what?
First rule out the easy stuff. Shut off the valves behind each toilet and check again. If the meter stops, a toilet is leaking, usually the flapper. That’s not a slab leak.
If it’s still moving, close the cold water valve at the top of the water heater and look again. If the meter stops, the leak is probably on the hot side. If not, it’s somewhere on the cold side, or in the line between the meter and the house.
Any of those can be a slab leak. That’s when a plumber with leak detection equipment can find it without guessing. See slab leak detection.
What the meter won’t catch
Drain and sewer lines aren’t connected to the meter, so a broken drain under the slab won’t show up here. If drains are slow or you smell sewer, see sewer and drain under the slab.
Meter still moving? Call or send the details.