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3607 Potable water system leak
Posted: May 9th, 2025, 8:29 pm
by Russdee
It seems that I have a leak somewhere in the potable water system services. The pressure pump runs momentarily on a regular basis without any of its services in use. Over the course of a week, when untended, over 80 gals. disappeared from the tanks ( I have a modified 105 gal potable water system) with water in a previously dry bilge. Is there any method or procedure on how to track down the leak that any one knows about?
Short of turning the breaker for the pressure pump off until a fresh water is needed I have no idea where to start
Thanks
RD
Re: 3607 Potable water system leak
Posted: May 9th, 2025, 8:34 pm
by Viper
Could be anywhere but the hot water heater is a common suspect and a good place to start, either a leaking tank, fittings, or the safety/pressure relief valve.
Re: 3607 Potable water system leak
Posted: May 10th, 2025, 8:21 am
by bud37
There really is no easy answer to this as the leak could be anywhere, there will always be the guesses but this is how I would tackle it.
Turn off the water system, Dry the bilge quite well, like towel dry. Put down some paper towels here and there. Remember, this leak could be coming from along the edges so don't just concentrate on the centre bilge. Turn the water on and watch closely for evidence of water on the towels and see if you can isolate the area it is coming from and give you the area to concentrate on. That should eliminate quite a lot. Using a bright light and a mirror here is helpful and feeling all the fittings with a dry hand is also helpful.
Look at it this way, by the time you are done you will know every area of your boat....bonus for later...

Good luck.
Re: 3607 Potable water system leak
Posted: May 10th, 2025, 11:02 am
by Carverlvr2
I just had a similar issue. After dewinterizing, I could not get a good flow from my faucets. Very aerated and pockets of air, even after several tanks of water run through. I knew it was sucking in air from somewhere but that could be anywhere. Shortly afterwards my forward bilge started filling with clean water and I noticed my tank emptier than I left it…ah hah! That narrows it down to the line between the pump and the tank. Pump area was dry. Tank area was dry. Started working from the tank forward and by time I got up super close to the pump, I found a 90° elbow that was leaking air/water and was just above an opening to the bilge so I would have never seen water pooling in that area. Removed the fitting, cleaned, re seated…viola! Dry and perfect water flow since. Hope that helps you narrow it down. Good luck and report back!
Re: 3607 Potable water system leak
Posted: May 11th, 2025, 11:54 am
by km1125
Do you still have the original grey water lines?
I had an 83 3607 and for many years kept finding leaks in the system. Sometimes it was a cracked connector at a fitting (the tub faucet inputs right at the rear of the engine room), a cracked one for the fwd shower (which leaked into the compartment below the dinette seating) and cracked fittings under various sinks. One time there was a leak at the "T" right behind the starboard fuel tank. The leak was so small you could not see the stream of water coming out, but you could put your hand there and feel it. That one drove me crazy for a while, because the water would pool outboard of the far starboard stringer (under the fuel tank) and only drain to the rest of the bilge after you put the boat up on plane and the water could run aft to an open limber hole. But then I'd see water in the bilge and have no idea how it got there.
Eventually I replaced ALL the grey stuff with color-coded PEX (red and blue). Never had a leak again, and had the boat 28 years in total. It's not that hard of a project to do either. I think I put some notes on the project in the "Projects" section of the forum.