Seawater supply to toilet: is vented loop required?

peaman

Sustaining Member
I am in process of replacing all hoses connected to the toilet and holding tank in my 32-3. Some sources (Peggie Hall) say that there should be a vented loop in the seawater flush line between the head pump and the toilet, but there is none presently. I believe the existing plumbing arrangement is original, as there are no signs of modifications. Presently, there is a short hose from the seawater intake seacock to the pump inlet, and another hose from the seawater outlet directly to the rear of the toilet. The pump is a Raritan PHII which recently replaced an older version of the same model.

Should a vented loop be in place between the pump outlet and the toilet connection? And if so, how would that be installed: specifically, how high would the loop need to be to be 8-12" above the heeled waterline, and where would the loop and hose best be installed while maintaining a clean appearance?
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
EY did not install any vented loops on our boat's toilet plumbing, either for water coming in or waste going out. Some folks prefer this way, and others do not. We have never been motivated to change.
 
Last edited:

Pete the Cat

Sustaining Member
What most production boats do is have the actual top rim of the bowl situated above the waterline and so a vented loop is technically not required if the valve is left open or if the internal head valves fail--and that stops a siphon effect. As you can imagine, this could be a problem if the internal head valves leak when the boat is heeled and the rim is below the water outside at some point for any period of time. I am guessing, without any evidence, that the production boat manufacturers think this is a less costly way to plumb a boat and probably would not result in sinking even if the bowl runneth over. To answer your question-- a loop probably not required, but not a bad idea if you can manage it with out trashing your boat with a lot of hoses. Another downside of a loop is that the smelly critters generally live in the intake side (not intuitive, I know) and putting more hose to create a loop is going to create more opportunity for places for them to grow. FWIW.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
I don't have vented loops, and it is indeed disconcerting offshore to see the water rise to the rim whilst (yes, whilst is Churchillian obsolete, but it entertains me) heeling. It is hard to disguise the plumbing of vented loops in a head. There they are! Puke will not overflow! Jolly proper!

But you can just keep the seawater intake closed except when the head is being pumped out. And It's only necessary when heeling occurs.
 

Bolo

Contributing Partner
When I installed my new Jabsco head two years ago I added a vented loop as per the installation manual. The old head didn’t have one but I figured, what the heck, let’s do it by the book. As for positioning of the loop, I put it up in the cabinet above the head on my E32-3. Drilled two holes in the bottom of the cabinet for the hoses and I may have used a 90 degree drill bit attachment because there was no room for the drill to get the proper angle. It’s a very useful tool, BTW, that I’ve used many times like to drill mounting hole in our narrow bilges. I don’t have a photo of the loop in the cabinet but in the image I’ve provided you can see the two hoses going up into the bottom of the cabinet.

No vented loop required for the discharge hose, as per the Jabsco manual, because that only goes to the waste tank and not a thru-hull. Can’t dump in the Chesapeake Bay and I’m 2+ days sail from the ocean.

6359E393-2C9A-43B9-9AAB-6DD3E88240BF.jpeg
 

peaman

Sustaining Member
When I installed my new Jabsco head two years ago I added a vented loop as per the installation manual.
That's a clean installation. Plus, I like that the aft position of the pump gets the bowl away from the bulkhead. Did you originally have a Raritan PHII, and if so, what was your motivation for the change?
 

Bolo

Contributing Partner
That's a clean installation. Plus, I like that the aft position of the pump gets the bowl away from the bulkhead. Did you originally have a Raritan PHII, and if so, what was your motivation for the change?
Yes, originally there was a Raritan PHII which was there when I bought the boat 15 years ago. It was old, a bit worn out and I rebuilt the pump twice with short lived success. In the end I felt that it wasn’t going to work right no matter how much I rebuilt any part of it and it was too close to the bulk head. The Jabsco gave me the opportunity to move to bowl away from the bulkhead and I think the up & down pump is better then the lever one, IMO. It’s a much simpler design.
 

light24bulbs

E30+ 1984, San Juan Island, Wa
I'm considering doing something similar eventually and replace the lines, because the current lines are smelly.

The previous owner says that if you leave intake toilet valve open it will overflow the toilet when heeled over.

Simply not leaving that valve open seems like a perfectly good solution as long as you trust yourself and your passengers to do it.
 

peaman

Sustaining Member
I'm considering doing something similar eventually and replace the lines, because the current lines are smelly.

The previous owner says that if you leave intake toilet valve open it will overflow the toilet when heeled over.

Simply not leaving that valve open seems like a perfectly good solution as long as you trust yourself and your passengers to do it.
Yes, the lines do get smelly over time. Apparently, no flexible plastic is entirely impermeable. It's an ugly job, but necessary.
There should be two valves to prevent the head from filling: One is the seacock, and the other should be on the hand pump. Some owners routinely close the seacock before leaving the boat. The valve on the hand pump should always be closed after the toilet is pumped (flushed).

You may want to include your boat year and model in your "signature" to help in model-specific replies. Some users also include boat name and engine model.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
FWIW: Do not let the head hoses (including the ones to and from the holding tank and hand pump) get over 20 years old.
And we do close both the intake and exit thru hulls whenever we are off the boat. Both sink thru hulls , too.
 

Pete the Cat

Sustaining Member
I'm considering doing something similar eventually and replace the lines, because the current lines are smelly.

The previous owner says that if you leave intake toilet valve open it will overflow the toilet when heeled over.

Simply not leaving that valve open seems like a perfectly good solution as long as you trust yourself and your passengers to do it.
Theoretically, the head should not run over when heeled unless the head pump intake valve or spring is not set properly or not doing its job. But the only way to ensure you do not get water pumped into the boat when heeled is to close the through hull intake valve. Even a vented loop intake could pump water over the rim--the vent only prevents a siphon effect.
I realize there is controversy about this-- but I tee my head intake through the sink drain on both my boats so that I have the option to flush with fresh sink water or with sea water. I leave the boat with fresh water in the lines and bowl and have never had a problem with smell on either boat. . My Tartan 37 was plumbed with this arrangement from the factory and I easily converted the intake on my Ericson 32-200 to connect to the sink drain just below the water line. This has the added advantage of eliminating a through hull fitting and the sink drain provides the vent in the intake line if you happen to forget. FWIW. I always thought that Tartan was smart to have this arrangement for intake, and that Ericson's arrangement for putting everything through the holding tank and eliminating the Y valve option was the way to go for head discharge. Others will think differently.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
Allow me to hugely second freshwater flush for the head, through the simple T.

Marine water stinks very quickly when left in lines or head. It is why the holes in the porcelain bowl that admit flush water turn black and develop stringy junk.

This was underscored for me again last week when I changed out a leaking saltwater foot pump. I use that pump in the slip for washing junk down the sink drain (OK, pipe tobacco ash ) and for years have gasped at the rotten-egg smell, even when being pumped two or three times a week. My recent inquires about sink removal here in fact were motivated by a felt need to change the supply lines to the foot pumps just to get rid of that ghastly odor.

But the odor was in the saltwater pump. New pump, odor gone.*

I suppose this may depend somewhat on the local environment, but if stinks, consider freshwater flush.

Saltwater is an adjective, salt water is a compound noun. Same with freshwater and fresh water. (Freshwater fish live in fresh water). I corrected this post after looking it up.

*for two weeks. Now it's back, just as before.
 
Last edited:

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I suppose this may depend somewhat on the local environment, but if stinks, consider fresh water flush.
I have been aware of this problem for years. Looks like we do benefit from sailing in fresh water. The intake hose to the head can still grow black mold-ish bits that flush on thru when we have not used it for a while, but the odor is nothing like the result of boating in salt water.
 

Bolo

Contributing Partner
Allow me to hugely second fresh water flush for the head, through the simple T.

Marine water stinks very quickly when left in lines or head. It is why the holes in the porcelain bowl that admit flush water turn black and develop stringy junk.

This was undrscored for me again last week when I changed out a leaking salt water foot pump. I use that pump in the slip for washing junk down the sink drain (OK, pipe tobacco ash ) and for years have gasped at the smell, even when being pumped two or three times a week. My recent inquires about sink removal here in fact were motivated by a felt need to change the supply lines to the foot pumps just to get rid of that ghastly odor.

But the odor was in the salt water pump. New pump, rotten-egg odor gone.

I suppose this may depend somewhat on the local environment, but if stinks, consider fresh water flush.
I’ll add another vote for flushing with fresh water to help control head smell. Even though the head in my boat can be flushed using sea water I rarely use it. 90% of the time when we do our “business“ in the head we reach over and use the flexible faucet/shower head to flush. It’s easy and no extra plumbing is required. The only time we use Chesapeake bay water, which has more then it’s share of organisms in it, is to flush at anchor where fresh water supply would be limited. Then under way the sea cock is always closed. I also used clear hose from the sea cock to the pump so I can keep an eye on marine growth. If it shows then I open the valve and pump fresh (bay) water through. You can see the clear hose to the right of the head in my previous image.
 
Top