Mike, about 20 year ago we added on to my mothers house, added a new water heater for the new bathroom and inside laundry. About 8 month later the elbow on the cold water side started leaking. When my father and I when to fix it, we found that the pipe and elbow had been clean but not glued. So my father had a word or two to say to his son in law that was suppose to have done the gluing.