Air In the FW Plumbing

Apr 25, 2024
667
Fuji 32 Bellingham
We had a vigorous day, yesterday - hours of beating windward - heeled over a bit too far much of time. Crew was doing dishes while heeled over about 12-15 degrees. The water stopped flowing like the tank was empty, but he didn't say anything at the time. He was a complete novice and just assumed the tank was not feeding because of the angle. And, we had our hands full, so he neglected to bring it up.

When things calmed down, I went to make some tea and discovered the pump was continuously running, even with the faucet off. I turned the faucet on and no water flowed (a bit of sputtering). We were heeled to port maybe about 10-12 degrees, at the time. I shut to pump off at the breaker and took a look below to see if I could see any obvious plumbing problems.

What I found was water flowing down from ... somewhere ... into the bilge. Not a lot, but a steady stream - enough to cause the bilge pump to run every couple of minutes ... maybe. Since this coincided with the fresh water issue, I assumed it was fresh water leaking ... probably out of the water heater tank at that point. So, I kind of wrote it off as being that, deciding to look again after 20 minutes.

About 20 minutes later, still/again on starboard tack, the water was still flowing and it wasn't warm and it wasn't fresh - clean sea water. So ... great ... it's coming in from outside ... not a great thing.

I will fast-forward at this point to avoid dragging the story out much more. The sea water ingress is unrelated and only happens when heel strongly to port. I still do not know the exact source, but the most suspected source is the sea water exhaust. That isn't my question. It was just a red herring that I ran into while looking at this.

Once we turned onto our downwind leg and the boat flattened out, I tried the FW again. It took a while to prime, but eventually started flowing again.

But, two things confuse me:

First, the FW tank is on the port side, about amidships, under the port settee, and we had about 1/3 tank. I don't think air entered the system from the tank. Though, I don't know which direction we were heeled when the swab was doing dishes. Had we been heeled to starboard ... maybe. The supply line coming out of the tank is just a couple of feet from the center line and the lowest part of the tank when heeled to starboard or level. It is hard to believe we were heeled so far to port as to allow air in there but ... maybe.

Second, the system took a long time to prime. I have emptied the tank before and then refilled, and it did not take that long to prime. It feels like there was something else going on there aside from simply a supply disruption.

So, my question is ... what am I missing? If the issue was not air entering at the tank, what else could it have been? If it helps, the pump is several feet aft of the tank and on the starboard side.