I plumbed the heads just that way about 4 years ago...following your
suggestion . And rinse w/ fresh water religiously before leaving the boat.
But we are greeted w/ a stench each time. Perhaps the intake lines need a
clorox treatment since the replumbing was not done for the first year, but
I don't really want to send clorox to the tank (discharge goes straight
there).

"Peggie Hall" wrote in message
news
Garland Gray II wrote:
Now that I think about it, the survey (it was a 6 month
old demonstrator boat) didn't make mention of this deficiency.

If the toilet is completely above the waterline, it wasn't.

It was almost completely below waterline.

In that case, it WAS!

I expect that the water between the vented loop and the bowl that is
higher than the top of the bowl eventually drains to the bowl, to be
replaced by air.

But not before it stagnates in the anaerobic environment inside the
hose...and could very well stay till it's flushed out if the wet/dry
valves in the toilet is working as it should. However, you're overlooking
the water that's also left in the intake tank between the thru-hull and
the top of the loop, that has nowhere to go till it's flushed out when the
seacock is opened again. I suspect that's where the worst of the problem
occurs.

It's easy to solve: Tee the head intake into the head sink drain. Flush
using sea water...then, when leaving the boat, after you've closed all the
seacocks, fill the sink with clean fresh water...flush the toilet. Because
the seacock is closed, the toilet will pull the water out of the sink,
rinsing all the sea water out of the WHOLE system (just pouring water down
the toilet only rinses out the head discharge line...it doesn't ever get
into the intake). Or, you can flush with fresh water all the time by
keeping the seacock closed and adding water to the sink..though you really
don't gain anything over just flushing all the sea water out before the
boat sits.
--
Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/store/custo...0&cat=6&page=1
http://shop.sailboatowners.com/books...ku=90&cat=1304