Two weeks ago, I had to replace the expansion tank on my hot water heater due to a small pinhole on the top. Ever since then, it seems like there is increased water pressure when I flush either of the two toilets in the house. In the master, you can hear like a banging in the wall as you flush. In the other bathroom it sounds more loud with an abrupt stop once the tank is filled. I have not noticed significant water pressure or pulsating water from any of the faucets. This was not issue before the expansion tank was replaced.
Is this normal? Does this usually take care of itself? Is there something I can do to reduce the pressure or does this mean there is something wrong with the expansion tank?
The pressure on the tank came precharged at 40psi. It was not adjusted at the time of the install to match the incoming water pressure of the house which measured 60-65psi. Due to this, I pressume that is why I may be having the issues. Will this be resolved if the expansion tank pressure is increased? Is it an easy fix to just add the air, or is it more complicated than that?