Fresh water – volume and pressure

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This topic contains 4 replies, has 5 voices, and was last updated by  Henry Dennig 9 months, 1 week ago.

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  • #8578

    We recently installed a cockpit shower with hot and cold water on the transom using one-half inch PEX. Volume and pressure of water pressure there is great. By comparison, water delivered to the head and the galley is a trickle. There are no filters in the way and we do not have an accumulator. The same 9 gallon per minute fresh water pump serves all lines. We measured 2.5 quarts at the galley sink.

    Has anyone every had this kind of problem? I am suspecting the PEX tubing is either too small (in which case, has the flow been like this forever?) or somehow restricted.

    Before we dig into things, are there any words of wisdom or relevant experience on other Great Harbours that we can learn from?

    Avocet, N37-08

  • #8579


    As a suggestion and from past experience; disconnect the water line where it connects to the faucet. Then check the pressure from the hose minus the faucet assembly. If pressure from line is ok, rebuild (cartridge) faucet.

    Paul Murgo
    The Rose, GH37

  • #8580

    Michael Sutton

    We have a similar problem at the galley. Yet, the head sinks and showers have plenty of pressure. I have cleared the faucet screen with no improvement, so, my guess is mineral deposits or some other blockage. It has been that way since we bought the boat. I plan to get to it but not any time soon… it is on the list.

  • #8582

    Chuck Truthan

    We have the same lack of pressure and volume at the galley sink. 4 weeks ago, I “back blew” the pipe system by removing the sink screen and then selecting hot or cold. (I tried but was not able to disconnect the water pipes below the sink as the piping was pulled too tight – not enough slack to push the pipe into the fitting to get it to release!) It DID make an improvement – but only for a short time (2 weeks) and is back to the same.
    I’ve not had the time to try and disconnect the faucet to see if there is a cartridge filter or what. Fortunately, there are water shut offs under the sink!

    Chuck Truthan

  • #8584

    Henry Dennig

    We have had a similar issue. Plenty of water in the showers and head faucets, but the galley faucet sucked!
    We took the Moen faucet off and have plenty of water out of the valves. I back flushed the Moen faucet and found “black particles” came out. Called Moen, they transferred me to the Black Particle department (their term) and he sent me a new faucet. 18 months later, same low pressure, so I replaced the cartridge and pressure is back. I did learn there is a flow restrictor in the Moen faucet and threw that away.
    While messing with the faucet, we bought a $16 cheap plastic faucet that is VERY basic with wide open flow. We keep that for testing.
    I did speak to Depco about stronger pumps..they said the 15mm PEX plumbing would be restrictive and the Whale / Seatech fittings might not like a 75psi pump, so we left that alone.
    I do plan to connect a PEX to Garden Hose adapter to various places and push dock water back into the engine room connection at the water pump.

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