The water company says I have a leak in my house, I have had 2 plumbing company's out neither can find a leak. All they say is it is on the hot side. When they close water off to the water heater the meter stops running. Can a faulty water heater cause this. I have had an increase in power bill but thought it was due to the cold weather here in the south. My meter reading went from 4000 usage to 36000 usage.