We have had several calls recently and meters reading water leaks. We wanted to share a Check list we found, to search for water leak culprits.
Water leak trouble spots:
1. Water softener equipment.
2. Water tank on commode:
A. seeping feed valve causing overflow.
B. ball or flap valve not sealing.
3. Water heater filling or leaking.
4. Dripping faucets in tub, sink, shower, lavatory, etc.
5. Outside hydrant or faucet open, leaking or dripping.
6. Hose in yard turned on or leaking.
7. Relief valve on water heater open or seeping.
8. Washer or dishwasher feed valve open or seeping.
9. Leaking pipes or fittings in house or in line between meter
and house.
10. Unknown lines in yard or to other outlets.
11. Swimming pool, fish pond, fountain, etc.
12. Water to air conditioning colling tower running or leaking.
13. Any equipment connected to water lines.
14. Service lines to out buildings leaking.
Original source can be found here