I am in need of some advice. I just bought a bank owned house "as is". It had a blown PRV that I had plumber replace before we closed (pressure was 120). I just moved in and replaced all the toilets with high efficiency "quick fill" models. Here is my problem: Every time I flush the toilets (and sometimes when I run the shower) the pipes pulsate in the basement (only while filling) so its not water hammer when the valves close. I can remedy the problem by slowing the flow to the toilets at the supply valves at each of these. *So I thought maybe the supply valve or washers were bad... replaced them. didn't work. Next; Lowered the water pressure to the prv (55PSI). The pulsating went away . Fully opened all valves and no pulsation. Today it is back again. A few notes: I have pinpointed the vibration to the PRV or Water Meter right above it. (they both shake violently). 2nd.... If my sprinklers are running this does not happen. I am going crazy.. any ideas?? Thank you!!!