Our new-to-us Oday 39 suffers from very poor water flow both in the galley and the head. Initially I replaced both faucets - a basic household Kohler faucet in the galley, and a Dura marine/rv faucet in the head. The pressure pump is an ITT-Jabsco Par belt drive pump (3.7 gpm) which I really like because it is much quieter than the diaphragm pumps we used (and replaced every two-three years) on our last boat. There is a small Shur-flo accumulator tank which I have properly pressurized to 20psi. The flow at the faucets is dismal when the system is fully pressurized, and almost non-existent when the pump cycles on. Today I replaced all of the 1/2" John Guest piping and fittings through the entire system with 1/2" Pex piping and fittings. The John Guest is 1/2" OD, the Pex is 1/2" ID. The only improvement, and it is marginal, is at the galley sink. The head faucet if possible got worse. I am wondering if I should rebuild the pump, although it seems to be functioning fine? I don't have a good way to test the actual pressure - it should be cycling on at 20psi, off at 40psi. When I checked the pressure in the accumulator for the first time it was low, after increasing it to 20psi, there is pretty pronounced pulsing in the water flow as the pump reaches full pressure. There are two 50 gallon tanks feeding the pump, from the pump the water goes through a check valve to the accumulator, then to a manifold which supplies water heater, galley cold, and head cold. Coming from the water heater is a line to the head with a T in the middle to serve the galley faucet. The pump is under the galley sink, midway between the heater and head. Distance from heater to head is about 21 feet. The previous water heater was an additional 7 - 8 feet aft of the current heater. Not sure what else to try??
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