jjspena
New Member
I have had this ongoing issue that has been happening since we moved into our town home a little over a year ago. I am in the HVAC field so I have some working knowledge of plumbing but this one has me scratching my head. My water pressure coming in used to be around 95 psi so I installed a PRV and an expansion tank on the cold line right above the WH then set my pressure and EX tank to 62 psi. The issue still is that I am still hearing an occasional bang, sometimes about 5 or 6 with in an hour for maybe an hour or two, when nothing is using water. Most of the time it tends to start a few minutes after water has been used and is now off. I have checked all my flappers, have even turned off all toilets, and ran test but still getting noise. My theory was that when the electric water heater was heating that it was creating expansion and movement but then I quickly remembered that I have an expansion tank. Please, some one help me on this one because it is beyond my expertise for sure!