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350 Mariner Fresh water leak

Posted: October 1st, 2018, 9:50 pm
by 650Guy
OK, I am almost positive I have a leak in my fresh water system, but not really sure how to get to the last place for me to get at. Here is my symptoms and what I have done:

Symptoms
* water accumulates in the fwd bilge whenever we are at the boat and water pressure is applied.
* No additional water accumulates during the week when we are away.

Areas checked
* all connections along fresh water holding tank are dry
* connection feeding vacu-flush toilet is dry
* Lines leading to the fwd part of the V- are dry.
* lav sink lines are dry
* Shower lines are dry

To me this only leaves the line that leads up to and under the V-berth bed. I'm assuming the lines have to do a 180 in that general area to go over to the lav area, but have no clue how to access them.

Am I missing something? Anyone have any idea how to check that area?

Re: 350 Mariner Fresh water leak

Posted: October 1st, 2018, 10:02 pm
by tomschauer
I believe the mariners are bow heavy, so any bilge water will end up in front, no matter where it enters the bilge.

A couple things to check..

Water heater relief valve

Shower sump / ac drain

Re: 350 Mariner Fresh water leak

Posted: October 1st, 2018, 10:10 pm
by 650Guy
They really are bow heavy...

I think I have checked the hot water tank and that whole area seems pretty dry, but maybe the A/C drain I have not traced that one down. Water in my bilges makes me crazy!

Re: 350 Mariner Fresh water leak

Posted: October 1st, 2018, 10:20 pm
by tomschauer
I don't know about your hot water heater, but my relief valve is piped to the bilge. Found mine was leaking the other year by some nice warm bilge water. Constant trickle when hot.

Re: 350 Mariner Fresh water leak

Posted: October 2nd, 2018, 7:09 am
by 650Guy
thats a good idea! I have not tried feeling the water! maybe its warm and it will luck out! thanks for the idea!

Re: 350 Mariner Fresh water leak

Posted: October 2nd, 2018, 9:04 am
by Midnightsun
Not knowing your setup what about the AC unit(2) mine are all plumbed into 2 different shower sumps. Are the sump(s) functional? Are the hoses well attached? My previous boat they simply had the AC unit empty directly into the bilge which was dumb IMHO, I did change this to get rid of the water.

Re: 350 Mariner Fresh water leak

Posted: October 2nd, 2018, 10:14 am
by bud37
650Guy wrote:Source of the post They really are bow heavy...

I think I have checked the hot water tank and that whole area seems pretty dry, but maybe the A/C drain I have not traced that one down. Water in my bilges makes me crazy!

What year is your boat ?.....I know mine a 2001 was supposed to have the AC drain go to the shower sump according to info on the electrical panel, but it goes directly out the hull side, also maybe follow the water lines that run up to the sink etc on the bridge....

Crawl into the space under the seat by the galley sink with a very bright light .....with the water pressure on, does the pump cycle as if it is losing pressure?

Re: 350 Mariner Fresh water leak

Posted: October 2nd, 2018, 11:01 am
by amanphoto
Have you checked the shower fixture? Do you use the shower on the boat?

Re: 350 Mariner Fresh water leak

Posted: October 3rd, 2018, 10:05 pm
by 650Guy
Thanks all!! First, I have a 2001 350 mariner. AND LOVE IT!!!

So spent the day trying to find this. Here is what did today:

    Completely checked the hot water tank
    Discovered its on its last leg, but not the source of the leak. - fresh water collecting in the bilge is cool to the touch.
    Kept the A/C unit off
    Added water pressure from the shore
    all bays in the hull aft of the center bays under the waist water tank remained bone dry
    looked down the port side of the hull behind the kitchen cabinets as far as I could, and found it to be dry
    removed the access panels under the bathroom sink, found it to be dry and no sign of water off the lines
    Removed the shower controls at the handle and all lines leading to it, were dry.
    Shower was not run, but all caulk was replaced

As I worked, the bay started to get water in it. Over a 3 day period, water levels would grow to just about the bilge pump.

I think this leaves;
* Water lines to the ice maker and sink up top
* Water lines that lead up to the V and 180 back to the sink & Shower

So how do I get at either of those?

Re: 350 Mariner Fresh water leak

Posted: October 3rd, 2018, 11:24 pm
by tomschauer
before you dig in to deep. Try using the on board pressure water and not dockside water. If the pump runs every now and then without you using water, something is leaking some where. If not, its something else. Don't forget to turn off the ice maker first.