E38 Head Plumbing Need Ideas!

[olsenjohn]

John - you still need a pump of some sort between the below the waterline thru hull and the tank. Maybe you assumed that was obvious. But you are correct, if there is no direct head to overboard path, you don't need the anti-siphon loop on the discharge side. Some say you need it on the intake side, but if you are using a fresh water flush method (basin drain connection) you do not need that either.

Yes, I assumed the manual plastic whale pump in between as you said, but I should have called it out. And correct also that the holding tank is lower. And I am using freshwater flush.

Absolutely great to hear I don't need it as the room in a 25 for plumbing is very tight. You guys are tight on 30+ footers, imagine running it in the 25.

Thanks for the reply!

 

[mkollerjr]

Installing an anti-siphon for the head intake needs to go on the pump discharge, so that wouldn't be under the sink. See attached photo. We did not install one, although if you are paranoid about it, it looks like it would be pretty simple to install one. It may look fairly ugly unless you try and conceal it by drilling some holes in the fiberglass behind the head, routing it up, and popping it above the waterline somehow.

 

[footrope]

Comments and some gaps in the plumbing discussion

Loren, I enjoyed your older thread when you were replacing plumbing and your holding tank. Fresh Air for sure. Steve's comments about the Whale pump causing odor because it contained some "matter" are worth considering. While we have used that pump legally a couple times in emergencies (that should be in quotes) we usually will change plans or plan ahead to find a pump out station every 3-4 days. There is no legal way to flush that manual or macerator pump with clean water unless you do extra plumbing or take other heroic measures to enable that. Macerator pumps seem less likely to produce odors due to trapped matter.

Reference mkollerjr's comment, the flush water intake system is not diagrammed well on any of these posts. Unless your toilet bowl rim is above the water line, you can fill the boat with sea water in certain conditions. If you leave the valve on the thru-hull for the flush water open, and the flip-to-flush valve on the toilet pump is not fully closed ... ? Yes, the bowl will begin to fill and could overflow. My toilet rim is above the water line, luckily.

Holding tank vents: A neighbor's E38 (another E38 is on my dock!) has his tank vent about 3 inches lower than mine is and he says that on a starboard tack with the rail in the water the holding tank can fill from the vent. A vented loop isn't easy at that location but he did add a horizontal loop on the underside of the deck. We'll see how that works.

 

[mkollerjr]

...I agree with the Whale Gusher pump as a source of odors. We took ours out and left it out. The bellows were pretty odor permeable on that pump...