I have had 2 different plumbers out to my house for the same problem and the problem was not fixed. Justin Scamp from Quality First came out and only listened to the obnoxious noise for a few seconds and said he was positive it was the PRV. He had it replaced in 1 hour and the noise I have been dealing with for over a year is gone! I am VERY happy with Justin's service and his friendly professionalism. I would ask for him again!