Switch Heads to Salt Water

Feb 3, 2014
94
Hunter 44 aft cockpit Miami, FL
I Have been told that I MUST have the factory built-in capability to use my fresh water heads on salt water in case I run out of fresh water. Is this true?
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
no, you dont have to.... when you run out of fresh water you can still use a bucket to fill the bowl so you have something to flush with.... or not use the head at all.

the option of using seawater to flush is a great idea, people have been using it for many many years to flush with.

depending on the system, using freshwater to flush with on a boat can have some complications that is highly undesirable... because bacteria can travel upstream to the source of the "fresh" water, which is the holding tank.
are you drinking out of the same tank that the flush water comes from?...
 
Feb 3, 2014
94
Hunter 44 aft cockpit Miami, FL
I was actually asking if a large Hunter owner could tell me if my boat was equipped to switch from fresh to salt (external) water.

To answer your question, Yes, the water to flush comes from the fresh water tanks. But I find it difficult to accept that so many builders are making such a huge "mistake". The smell associated with marine heads is really mitigated with a fresh water system in our experience.
 
Feb 26, 2004
23,093
Catalina 34 224 Maple Bay, BC, Canada
The electric heads can take fresh water, manuals cannot due to the bacteria issue previously mentioned.
 
Jan 4, 2006
7,308
Hunter 310 West Vancouver, B.C.
The electric heads can take fresh water, manuals cannot due to the bacteria issue previously mentioned.
Stu,

Without a backflow preventer, why do you say that an electric pump is safe from backflow (of black water) whereas a manual pump is not ? Given there IS a backflow preventer present, aren't they both safe ?

Not too familiar with, and never really looked at fresh water flushing on our boat as:

(a) fresh water is a precious commodity with our lack of marinas up north.

(b) it's much easier to flush your sea water inlet hose with fresh water from the sink drain.

Thanks.
 
Sep 25, 2008
7,510
Alden 50 Sarasota, Florida
Backflow flow preventers fail and can leak. Happens frequently even in heavy duty preventers which is why they require annual maintenance in industrial applications. They type used in most boats is frail by comparison.
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
If you don't mind drilling another hole in your hull, you could put a Y in the head intake line going to a new seacock. One of the advantages of the fresh water flush is one less hole to sink you. Or you could run out to a tee on a sink drain. As long as the tee is below the water line, that would work, but it is another failure point.
 
Dec 2, 1997
8,971
- - LIttle Rock
I Have been told that I MUST have the factory built-in capability to use my fresh water heads on salt water in case I run out of fresh water. Is this true?
No, it is not true...you can always use a bucket to flush any toilet, manual or electric, whether designed to use pressurized fresh water or raw (sea/lake/river) water. However, there is a system that, with the addition of a remote intake pump and the right electrical and plumbing additions, will allow toilets designed to use fresh water to switch to sea water at will...however it's a bit pricy.

As for whether it's safe to connect a marine toilet to the onboard potable water system:

NEVER connect any toilet designed to use RAW water to the onboard fresh water system. That cannot be done without risk of polluting the potable water supply, damage to the toilet, or both. And don't fool yourself into believing it'll be ok if you don't drink the water from your tanks...you ingest a lot more of it than you think you do... You wash your hands in it, then pick up a sandwish...rinse out a cup or glass with it, and then fill it with your bottled water....it gets on your lips when you wash your face....you don't want to risk using water from the toilet bowl for any of that.

However--
Any toilet that's designed by the manufacturer to use pressurized fresh water CAN safely be connected to the onboard potable water system. The toilets are designed to include the necessary siphon breaks, backflow preventers vacuum breaks etc.

Until 2014 only electric toilets were designed to use pressurized flush water. The Raritan "Fresh Head," introduced last summer is the first MANUAL toilet designed to use pressurized fresh water. It's available as both a complete toilet or a "conversion" (everything south of the bowl). http://www.raritaneng.com/product/fresh-head/

Doesn't look like SBO's online store has it yet, though...ask for it!
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
I was actually asking if a large Hunter owner could tell me if my boat was equipped to switch from fresh to salt (external) water.

To answer your question, Yes, the water to flush comes from the fresh water tanks. But I find it difficult to accept that so many builders are making such a huge "mistake". The smell associated with marine heads is really mitigated with a fresh water system in our experience.
it seems we all missed the actual question in your question...

you are actually asking if your boat has been equipped from the factory with the option to use seawater for flushing with?.... and although I now understand what you are trying to find out, I dont have the answer.

hopefully someone else can offer you some enlightenment:D
 
Jun 4, 2004
1,087
Mainship Piliot 34 Punta Gorda
To try and answer your question. I do not known your boat specifically but I would be surprised if your boat came from the factory equipped for both fresh and sea water. You should be able to run down the piping and determine its capabilities. There would be valves you would have to open/close to make it work.
BTW, unless you do a lot of cruising in the Bahamas where the fresh water is scarce you should have plenty of fresh water on board. And if need be you can use the pail approach if sufficient fresh water is a problem.
 
Feb 3, 2014
94
Hunter 44 aft cockpit Miami, FL
To try and answer your question. I do not known your boat specifically but I would be surprised if your boat came from the factory equipped for both fresh and sea water. You should be able to run down the piping and determine its capabilities. There would be valves you would have to open/close to make it work.
BTW, unless you do a lot of cruising in the Bahamas where the fresh water is scarce you should have plenty of fresh water on board. And if need be you can use the pail approach if sufficient fresh water is a problem.
That was indeed my question. WhenI get back on the boat I'll check the schematics. I appreciate the reparte, however. It is always stimulating and enlightening on this site!
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
I do

I can use salt or fresh water in my sea era electric head and it depends what
head model you have but all manual heads are usually hooked up to salt water
from the factory and that is what I have and what I do is I added a spray hose
like they have on home sinks and added the spray hose into my sink not to the head and always use that to add to my head for flushing and so some day if on a long trip and running low on fresh water I can turn the value a thru hull to use salt water.
Using fresh water is so much better for the head and less smell too.

Nick