When we moved in, we had pipes that would clank / whine / sputter loudly in a downstairs wall in the morning.

It has went away, but I’ve lost track of what change did it. We’ve changed out the faucets, the toilets, the hot water heater, we’ve bled the air out of the lines a couple of times for various reasons. Probably one of those things fixed it, but I have no idea which one.

We haven’t switched out the water pressure valve though, so that wasn’t it in our case.