We live in a 3 year old house and when we flush any of the 3 toilets, there is now a continuing thumping noise that is coming from inside the water heater closet in the garage.
There is a water pressure adjuster screw in one of the copper water lines, and I tried to adjust it, however, either the water pressure would be way too low when I got the sound to stop or it would continue to thump when I got the water pressure adjusted to an adequate level. How can I stop this thumping noise? I would appreciate any and all help!

Thanks!

John

Before we even start go down to your hardware store and purchase a hose bib pressure gage.(see image) and let us know what the PSI is coming into your house? What type of water heater do you have? Gas or electric? Get back to me , Tom