fresh water system leak/ holding tank issue...where to start

[NikM820]

Noticed my fresh water tank was empty yesterday after filling it last week just sitting on the lift. When I turn on the water pressure, the pump runs much longer than it ever had and I hear a constant hum when the water pressure switch is on. The pumps not running like it does when someone is using the fresh water, you can just hear a slight buzz. Not sure if that is relevant. Another thing was after I shut it down I flushed the toilet and got a pretty strong sewage odor on the deck.. It didn't last long but it was obvious. I'm up for my 100 hr service and was planning on letting my mechanic handle it, but he's running behind. Any advice on where to start would be great, although if this is better left to the professionals, let me know.
Thanks guys
Nick

 

[bhemi]

Re: fresh water system leak/ holding tank issue...where to s

You have to ask yourself where all that water went. If you have a leak it will end up in your bilge. I had a persistant source of water in my bilge that drove me crazy. It turned out the fresh water pump was leaking in the body of the pump only when under pressure. So when I pressurized the system the pump leaked unti lthe pressure went down. No pressure - no leak. Not until I pulled the panel and turned on the pump and sat and watched everything did I spot it.

 

[Fishtales]

Re: fresh water system leak/ holding tank issue...where to s

HI,
Some ideas.

1.) Does your head use freshwater or sea water. I'm assuming fresh. Is the holding tank full? Maybe there is a leak in the water feed and it is filling the tank slowly. If you flush into a full tank some of the liquid could be getting in the vent thus the smell. If not, maybe the lack of water pressure and thus water is causing the smell problem.
2.) Is there any water in the bilge?
3.) Empty head, fill water system and pressurize. First check the faucets in the boat. I had an issue where after a few years the line that feeds a CW side of the faucet started leaking. I needed to re-do the connection. It was a tough find as the water ran back down along the rubber feed line into the bilge. It took a while for it to make it back to the rear of the boat. Also check the front bilge is present. On my 300 the front section will accumulate water before the aft.
4.) Check the sprayers at the aft washdown station and rigging station if you have them. I had to replace one entire sprayer, reset one of the o-rings and also used nylon plumbers tape to stop a leak on the threaded sections at one time.
5.) Get your manual and trace your water system. You need to know all the connection points and check them one by one.

Let us know what you do and what you find.