Using Built-in Leak Detector
Temporarily stop using water by turning off all water-using devices such as showers, water closets, washing machines.
Raise the protective cover of the water meter.
Observe the triangular disc (usually red) commonly called the “leak indicator.” If the red triangle is spinning, your water connection has a leak.
For water meters without indicators, check if the meter dial hand is moving. If it is, water is running somewhere in your system and there is a leak. Check toilets, washing machines, faucets to identify where the leak is.