just had water dept out to check causes of low water pressure in our house. answer was our hot water heater could be filled with sediment and we should change it. pressure is bad for both hot and cold and ALL fixtures throughout house. house is 12 year old ranch in a high pressure area--across the street from water tower--yet pressure has always seemed low, just lately seems to be getting worse. all valves are fully open, water guy says we have 44psi to the house and switched out water meter, but no help. anybody have any ideas? is water heater really the problem? or is there something else i've overlooked?