What Can I Do if I Have a Leak & Don't Know Where it's Coming From?
A series of simple tests will identify the most common types of leaks:
Double-check to see that all water was turned off. What about automatic refill usage, such as the pool, fountain, water softener, automatic ice maker, and hot water heater?
Is the leak indoors or outdoors? Turn off the master shutoff valve, and if the flow indicator is still spinning, your leak is outdoors between the meter and the shutoff valve. Locate and repair underground leaks as soon as possible, because if left unchecked, they could cause property damage.
If the leak is indoors, first check the toilets. Shut off all toilets using the valve at the wall behind the toilet, and check the flow indicator. If it stops spinning, at least one toilet is spinning. Turn them on one by one, checking the flow indicator after each one; more than one toilet could be leaking.
Check other appliances, including water softener, water heater, water cooled air conditioner, and automatic ice maker. Almost all have bypass valves. Turn them off one by one, checking the meter between each.
Turn off the master valve to the irrigation system and check the meter. This will identify a leak in the headworks of the irrigation system, but not in the distribution pipes or sprinkler heads.
If none of these tests locate your leak, it's time to call the plumber.