my new house that was built in the 70's... when the water is turned on inside or out it make a very loud hammering sound until the water is shut off
Could it be the Pressure regulator ??? :confused:
Sounds like a washer or large piece of debris is hung up somewhere. If it does it hot or cold than it than it should be somewhere on the cold water main before water heater, it could be something else but I'd troubleshoot it as a serious restriction in the water supply. I had a washer blow out and get stuck at the water closet supply valve once and when you flushed the toilet it sounded like the whole house was coming down.