In most cases the water meter is *not* faulty.

In some cases, one house with a garage or whatever has been split into two.
Or a business with two buildings has been split into two separate
properties. BUT they don't separate the water lines! It is possible that you
have a water line going to a neighbor. But only if at one time the two
properties were one. Symptoms of this are constantly high water bills, water
use when your house is vacant. Or neighbors house is vacant, then occupied
and suddenly you have a higher water bill.

Other than that, it is a leak somewhere. I would find where the water lines
go, enter house, etc. and install shut off valves. When it is happening,
shut off a valve to just the house for example while leaving the yard water
on. Then you can eventually narrow down the leak.