I bought a 2002 456 CC last year and am spending the next few seasons getting to know her before doing any prolonged cruising around New England. I noticed a few months ago that my freshwater started to smell and finally got around to flushing the system. I have the boat on a mooring, so I procrastinated. Well, when I finally got around to it the lines had some an obstruction...probably some sort of growth in the tank that got lodged in one of the lines. I ended up back-blowing out the lines with compressed air, but in the process was amazed at how much water kept coming out of the lines when they were under "back pressure." I don't believe there's an accumulator tank in my system (in normal use the pump always runs when I turn on the water), but wondering if the hot water heater was acting as an accumulator. Any thoughts or experience out there? Semper Sailor