We just bought a house that had been vacant for some time and had been winterized. There are 4 bathrooms in the house, 2 up and 2 down. The main floor master bath's water pressure is fine in all areas. The main floor powder room has little to no pressure at the sink. The 2 baths upstairs have fine shower and toilet pressure, but again, little to no pressure at the sinks. Any thoughts? Thanks!