I have noticed this mostly with my washing machine, but when it initially fills, it sends water to it in spurts (on-off-on-off) for a few seconds at a time and the first two shots of water really rattle the pipes. If I run some water in the sink while it is filling, it doesn't do that. Anyways, I mentioned this to someone in the plumbing section at the hardware store and he suggested I get a pressure gauge to test the pressure. I hooked it up to the washing machine connector and it registered 55 but the directions on the gauge said to leave it for awhile. I came back later and it was up to 115 which is as high as it has gone. I do have a pressure regulator but shouldn't that keep it at 55 all the time? Does that mean it is bad?

I have a 3 floor house with the top floor rented out. I'm going install some PEX manifolds one for each floor but an wondering where to position the 3rd floor one. The ground floor ones can go in the crawl space. The 3rd, can it just go in a cupboard? 3/4 PEX from main to manifold then 1/2 to fixtures