Tracking down fresh water leak?

[SJI Sailor]

We have a fresh water leak on our new C30 that I have been trying to track down for 3 months (including 4 service visits). Before I do more, I'm wondering if others have suggestions that might help. Apologies for a long post, but I want to share my thinking -- perhaps to get help and also just to document my thoughts for anyone else!

Here's what's happening and what I've already done:

1. It is leaking about 10 gallons per day, with the pump off. When the tank is filled, it will be at half-tank (30 ga) in 2 days and empty within 5 days. The bilge pump activates and pumps out water on every automatic cycle until empty.

2. We found and fixed one issue, a cap that on the splitter by hot water heater that had not been capped properly by the factory. However, the leak persists.

3. I have added red food coloring to the tank and placed tissue paper at all suspected connection points, and at the holes that I could find for the bilge connection. Noting got wet or turned red that I could find.

4. The dealer installed a fresh water connection for the head, leading from the tank to the head supply in the engine room. As far as I can tell, that is all OK.

It seems that there are three places it might leak, given that the pump is off:

1. The regular cold water supply between the tank and the pump. However, that entire area remains dry. I don't see how this could leak 10ga per day and stay dry.

2. The new supply to the head, which runs through the engine room. This seems most likely, but I can't find it with the tissue/color diagnostic.

3. A hole in the tank that we can't see, draining into the forward bilge. This seems possible and would be consistent with the fact I can't find water anywhere aft of the tank (except in the bilge!) I have no real idea how to check for that.

My plan is this:

1. Remove the head supply and cap it. See if the tank continues to empty.
2. Remove the supply to the pump and cap it. See if the tank empties. If so, then I would assume it is a leak from the tank?

Is there anything I'm missing, or other ideas on how to detect it? Thanks in advance!

P.S. Warranty service has been almost no help with this (e.g., it took 4 visits just to fix the leaking cap). I have concluded that I have to diagnose everything myself, and then also directly supervise the work, to have much hope of warranty assistance. So that's what I'm trying. At least I learn something along the way.

 

[Connerkip]

Just a clue which may help. The leak is at the level the water drains down to, not above. So if the tank empties, the leak probably wouldn’t be any where above the empty low level of the water.

 

[BB marine]

A few questions that were not clear. Are you finding red water in the bilge? How is the freshwater connection made to the head? The fresh water feed to the head should be direct to the head. The flush should only work with water pressure from the pump and there should be an isolation solenoid between the fresh water tank and the head. Raritan makes a conversion kit to do this. Is there a chance that the installer installed a tee to the assisting raw water flush and the water is syphoning out of the tank to the raw water inlet. Thats a long shot because that would be a very poor conversion. Another option for trouble shooting your issue and a good idea anyway is to put a shut off valve between your tank and pump. I did this on my boat so I could clean the fresh water pump screen with out emptying the tank. If your water leaks then its your tank. If it doesn't you have an issue of the water syphoning from a low point in the water line. If you always had the issue most likely a leaking or cracked fitting. If it started after head conversion I'm isolating that from the system.

 

[SJI Sailor]

Thank you, BBmarine & Connerkip! I answer the questions below (mostly for posterity, I hope).

First: huge thanks to Andrew Custis at RT/Cutwater: their crew came and diagnosed the problem! There was a hole in the fresh water head conversion line, located where that hose runs in front of the engine, very difficult to see. The hole was caused by the dealer's installation of the line not being secure, such that it drooped and contacted the engine belt, which then wore a hole in it.

Now, to the other questions:

1. Yes, there was red water in the bilge but I couldn't find any elsewhere on tissues that I placed near all the fittings. [see diagnosis above]

2. Freshwater connection to the head was made by running a new line directly from the tank -- using a new, second tap on the tank that bypasses the pump. That runs to the freshwater line in the engine room, where it connects to the line to the head, replacing the original connection to the raw water strainer. Yes, they installed the toilet conversion kit.

3. Yes, it was below the level of the tank, and -- if RT hadn't come out to find it -- Isolating the fresh water line would have revealed it.

I would note that the RT crew had a tank pressurizer, which also seemed to help. After checking all the fittings, they pressurized the tank (I think, judging from the photo). The spray was pretty obvious looking in front of the engine.

Unfortunately, since it was a dealer issue and not an RT issue, I'm back to the dealer to try to remedy it. At least we know what the issue is! And it was great to have the checkup from RT 🙂