Ace Pelizon Plumbing was called out on a water hammer noise on washing machine line. Ace Pelizon Plumbing found valves for washing machine on turned quarter of the way on. Turned water on to valves fully and could not get water hammer to occur again. Ran machine though full cycle. Spoke with customer about securing lines in attic crawl space above home. Also spoke with customer about water hammer arrestors for washing machine. No further follow up unless customer would like tech to inspect and secure piping in attic. Water pressure 75psi at regulator.