Hi, when I run water in second floor shower I can hear a drip in the wall on the opposite side of the house. The only plumbing on the drip side is the meter, the kitchen sink and a hose bib outside, which exits the basement directly off the meter. Line from meter goes first up to kitchen then continues to water heater on opposite side of basement and up to first floor bath and second floor bath. I ran water with the drain stopped so I don't think it is the drain. It seems like to far of a run to make it from one end of the house to the other and there is no ductwork on that side of the house to drip from. Any suggestions? Thanks!