Sounds like you probably have high utility bills other that water if the hot water is involved. Would suspect you have a leak somewhere after the water heater, if you are on a slab it is probably under the floor. From what you said that the neighbor was aware there was a problem, you would suspect that the seller did not disclose everything they knew was wrong with the house. My first call would be to a plumber, the second to the broker who sold the house. I would suspect that the state you live in has disclosure laws.

: I just bought a new(used)home. I can hear water flowing (and see on the meter)after I turn off any fixture hot or cold. The only way to stop the meter is to turn off the water TO the hot water tank. I let the air out of the expansion tank and that seemed to slow the flow. The neighbor told me that the previous owners had high water bills.
: I cant find a leak. What is going on?
: Is it possible to send water back through the meter and the have it cycle through again?