Fresh water system trouble

My fresh water system slowly looses pressure and must recharge somewhat frequently (about every 30 minutes or so). Until recently the system would only need to pressure up when water was being used in the galley or heads. When this happened a couple of years ago, I had a leak in one of the lines. It was obvious. I could hear it hissing which led me to the location and a repair was made.

This time I can't hear or see a leak in the pressure side of the system. Is it possible that I have water leaking back into the other side of the pump and the static water storage? How would I troubleshoot the system to determine the problem? I don't know the age of the current system. It's quite possibly as old as the boat or 27 years.

Trace every line and connection for moisture...sometimes the leak is so tiny a mist is all there is and a slow drip wherever it collects...maybe just a drip though.

Also make sure if your engine heats the hot water...that you aren't getting more coolant in your engine because of a leak in the exchanger part of the hot water heater.

Barring those...then look at the pump... if you can...hook a sort length of hose on the discharge side and a ball cock valve. turn on the pump and let it sit...if it cycles...and no moisture is present...then it's a internal pump leak (though I'm not sure how that occurs)

Thanks. I'll check the lines very carefully. Also, I was just reading about fresh water systems and now realize that there is a check valve in the pressure side after the pump and accumulator tank. I wonder if that check valve is leaking water BACK through to the supply side of the pump (non-pressured side).

This should be a fairly easy fix. Tap off the pressure line near the pump. If the pump holds pressure start looking down-line.

That water is going some where. Look for any accumulation in the bilge. Leaks can fool you especially small ones. Surface tension can cause the water to follow the piping to a low point and then drip.

Also., make sure you do not have a dripping faucet, an icemaker using water, a leaky freshwater head, a leaky freshwater deck wash, or a leaky deck shower, etc, etc.

Thanks, guys. I'll follow all your suggestions over the next couple of days.

Giggitoni said:

This time I can't hear or see a leak in the pressure side of the system.

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Ray, I had a similar problem a few years ago that almost drove me to the rubber room. Everything I looked at checked out but every time I went to the boat and turned the main DC breaker on, the FW pump ran for about 10 seconds and shut off. A few minutes later, the same thing. I lived with it for a couple of weeks but one day when I opened the anchor locker to inspect my rode, there it was. My FW wash down hose was leaking just enough to cycle the pump. Since then, I've had similar problems with the transom hot & cold water shower leaking. Two areas that I pay little attention to and two areas where a leak goes relatively un-noticed.

Good hunting!

"Is it possible that I have water leaking back into the other side of the pump and the static water storage?"

Yes it is possible, even likely. There are check valves in the pump. They get old and leak. Leaking valves cause a problem exactly as you describe. If you can't find a leak on the pressure side, rebuild the pump.

psneeld said:

Barring those...then look at the pump... if you can...hook a sort length of hose on the discharge side and a ball cock valve. turn on the pump and let it sit...if it cycles...and no moisture is present...then it's a internal pump leak (though I'm not sure how that occurs)

Click to expand...

I struggled with this issue for several seasons. I even went so far as to put a switch near the sink so I could shut off the pump easily and not have it cycle every few minutes. I searched high and low and could find no water leaks. I finally installed a new pump and the problem was cured.

HopCar said:

"Is it possible that I have water leaking back into the other side of the pump and the static water storage?"

Yes it is possible, even likely. There are check valves in the pump. They get old and leak. Leaking valves cause a problem exactly as you describe. If you can't find a leak on the pressure side, rebuild the pump.

Click to expand...

+1

When I did offshore sailing we would mount the FW pump on a piece of ply so it would make noise when operating , as a trouble preventive measure .

On out bus conversion we cant hear the pump , so mounted a wire from the ON side of the pressure switch to a light in the galley which is ON while pumping.

HopCar said:

"Is it possible that I have water leaking back into the other side of the pump and the static water storage?"

Yes it is possible, even likely. There are check valves in the pump. They get old and leak. Leaking valves cause a problem exactly as you describe. If you can't find a leak on the pressure side, rebuild the pump.

Click to expand...

For what it's worth: I have two identical pumps (PAR MAX). One has this exact same problem, one does not. They are both the same age. I've tried rebuilding the leaking one but to no success.

I think the only possibility is replacing the pump, much as it pains me.

Scott Welch
Island Eagle

I think the only possibility is replacing the pump, much as it pains me.

PAR is usually the problem

How is the T&P valve on the hot water heater?

I'll be troubleshooting the system tomorrow. Thanks for your suggestions. I'll report back so all can learn. That's why we're here, I guess.

When I had my second problem with my freshwater system on my sailboat (1976 model), I replaced all of the hoses and some of the fittings. That was 6 years ago and no problems ever since. Apparently, the previous owner had problems also or was just plain cheap. What should have been a long run was actually several small hoses with connections. Sometimes it's easier to replace than looking for the leak.
BTW, You might also want to check closely around your hot water system.
This will be one of those times you will have wished you married a left-handed midget.
Good luck and have fun.

IF starting from scratch 5/8 copper tubing with flair fittings for 99% of the runs is first choice.

This independent, eye-witness party has verified that Ray (Giggitoni) with the assistance of Al (FlyWright) have corrected Mahalo Moi's fresh-water leak. After the repairs, the water pump did not activate during the three-beer (each), two-hour observation/test period.

Someones got a stalker........

rochepoint said:

Someones got a stalker........

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No. Someone made an invitation.

You can't rush the testing phase. Quality control is required for safety's sake!!

Thanks for the testing fluids, Mark!!

Thanks to Al and Mark my problem is solved. A cold water line running aft behind the port fuel tank and the master cabin head cracked at a joint causing my leak and loss of pressure. We replaced the old line with new and the problem is solved. As mentioned above the best part was having a few cold ones while waiting for our fix to fail! It didn't... Again, thanks to Al and Mark. The fix would have been difficult for one person.