I hear in the wall what appears to be a pinhole leak in a pipe, but, I have no water leaking anywhere. ( I cut out drywall next to one of the pipes where I hear) It’s DRY! With no water being used in the house, there is minute amt. registering on meter, (next to nothing). With the hot water pressure valve on top of water heater turned off, usage on the meter show NO usage, but, I can still hear hissing in wall.(Hissing stops when I turn off main water valve outside the house.) What’s up??

–Ellen

Ellen, it sounds (no pun intended) like you may have a leak. If you did have a pinhole in your piping system, chances are the water loss is too low to be noticed on a water meter’s readout (dial), and you would also have water showing up somewhere (unless you have lines buried below ground). The best thing to do is call a plumber who can come in and perform a hydrostatic pressure test -which is safer then a compressed air test.

-Brian