Wait a sec...

A vented loop can be made from half of a 2 part "P" trap intended for use
under your kitchen sink. The proper style has a drain plug on it's normal
bottom.

The plug may be fitted with a shraeder valve, like on your bicycle inner
tube or car wheel if you care to roll your own. The shraeder valve must
be adjusted for a very low pressure seal by adjusting it with a shraeder
valve tool. You should be able to blow through it, but not suck.

If I'm understanding what you're saying, it should be just the
opposite...'cuz the function of a vented loop is twofold...1) it creats
an arch in the line above the waterline...and 2) it's suppose only alow
INTO a line, nothing out.

The vented loop is created by mounting the trap upside down on the top of
two vertical pipes connected to the remainder of the piping in use. If
vibration tolerant couplings are used, rigid pipe may couple to other
piping, or semi flexible plastic pipe. I would use an MJ, or mechanical
joint Have used several with excellent results. The MJ was invented for
the Diefenbunker, nuclear defence against toilets backing up with over
pressure shock waves. The p trap should be situated at a point that does
not usually go below the waterline, but that is negotiable. It's function
is to allow low atmospheric pressure inside the piping to "suck in" air,
thus defeating any syphon effect which would otherwise occur.

Wouldn't it be a lot simpler and cheaper to simply drill a hole in the
trap and buy an air valve to put in the hole?

Proper anti syphon loops are available in cast platinum at marine stores.
Lesser metals like bronze are almost as expensive.

PVC vented loops are also availalble, and priced pretty reasonably.


You should be able to see if the head is pumping water into it's self when
you pump the pump. If it is, flip the little lever switch you will find
if you look, and pumping again, observe the head is pumped dry and your
tank will not fill so quickly.

Simply put, the most water efficient way: ahead of use, pump the head a
couple of times to wet the bowl...switch to dry. After use, pump enough
times in the dry mode to move the bowl contents all the way to the tank
(or out the thru-hull if at sea beyond the "3 mile limit")...switch to
"wet" for only enough pumps to rinse the bowl...then back to "dry" to
pump the "rinse water" all the way through the system.

Before you ask...any marine toilet that's working anywhere near spec can
move bowl contents at least 6' in the dry mode. If your tank or
thru-hull is significantly further away than 6', it's a badly designed
system.

you will need to replace, or possibly only clean the duck billed,
or joker valve.

As a live-aboard, replace it once a year...the average "weekend warrior"
should replace it at least every two years.

Buy one, since you will need a spare, then disassemble
the pump to replace it.


Why should you need to do that? The joker valve is in the head discharge
fitting, which isn't part of the pump, but only attached to it.
Replacing a joker valve only requires removing the screws that hold the
discharge fitting onto the pump.

If the old one is torn or warped you will need to
replace it, if not, you may be able to clean it.

If it's more than a year or two old, the slit will no longer be a slit,
but a hole...no longer able to function as the one-way valve it's
designed to be. Regardless of any other condition, if you can see ANY
daylight when you look through it, replace it.

I've never seen one torn that shouldn't have been replaced at least a
decade earlier.


Three lobed valves mimic heart valves, but without ligaments, are not as
reliable as possible.

Joker valves don't have lobes...the most common are a cup with a single
slit...a few are a cup with a + in the bottom instead of a slit...but
they're all just cup shaped doodads with a flange (that doubles as the
gasket between the fitting and the pump), a single - or + slits in the
bottom, and "lips" on the outside of the cup.

Crap overboard when you can. A flexible snow slider carpet may be of
assistance keeping topsides clear for neccessary bodily functions. It can
be towed by floating line to rinse, and seized up using the commissionaire
knot, a crochet, over the bulwark to be used.

Wouldn't a bucket on a long line be a lot cleaner and easier?

As for the rest...you have a wonderful imagination, Terry..but not a lot
of practical experience. If I'm wrong about that last part, please send
demonstration videos shot in 4-6' seas at least 20 miles
offshore...I'll add narration, send 'em to "America's Funniest..." and
split the take with you.

--
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

On 27 Nov 2005 17:13:17 -0800, wrote:

I just bought a new boat (to me) and have some head questions.

First some info:

Boat - Hunter 34, 1983

Head - Jabsco manual head

Now my problems and questions:

1. My toilet is filling up with water after it is pumped dry. I am
assuming this is fresh water (lake inlet) but am not usre

On most sailboats, the bottom of the head is below the waterline, so
the outside water is likely to flow (or seep) through the pump into
the bowl. If it looks like the water will overflow the bowl while
sailing, it may be necessary to keep the intake seacock closed except
while flushing the head.

2. My holding tank seems to be filling up a lot faster than it should.
I have about a 20 gallon holding tank and it is full after a day sail
with light use. Keep in mind this includes a week's worth of sitting
without use.

3. I'm not familar with one part of the unit...Right next to the head
there is a manual pump. A hose comes in through a thru-hull and does a
loop that wraps back through the pump and to the holding tank. Is this
to pump out of the tank to the lake or the opposite?

There should be a pump immediately to the right of the head bowl, and
mounted on the same pipe that supports the bowl. This pump has two
parts, and will pump outside water into the bowl for flushing, as well
as pumping waste from the bowl to the holding tank. Do you have a
second pump there?

I would think that the only thing that can get into the holding tank
is what you pump there while flushing the head.

If you are on the Great Lakes (or probably most lakes), you should not
have any direct connection from the holding tank to the outside water
- the only way to empty the tank should be via a deck fitting to
shore.

However, if the boat came from a coastal area (particularly in
Canada), there may be provision to pump out to the sea (or lake) -
this could possibly provide an alternate route for water to enter the
holding tank.


Any help would be appreciated.

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

Peter Bennett wrote:
On most sailboats, the bottom of the head is below the waterline, so
the outside water is likely to flow (or seep) through the pump into
the bowl. If it looks like the water will overflow the bowl while
sailing, it may be necessary to keep the intake seacock closed except
while flushing the head.

Productions boat builders put intake seacocks in locations that can make
that so impractical as to be impossible. My guess (till I hear more from
him) is that a) he doesn't know what the wet/dry lever is for...he's
been leaving it in the wet mode all the time...b) there is no vented
loop in the head intake (which should be between the pump and bowl,
btw...not between the thru-hull and the pump)...and c) he doesn't know
that all thru-hulls should be closed when leaving the boat.
There should be a pump immediately to the right of the head bowl, and
mounted on the same pipe that supports the bowl. This pump has two
parts, and will pump outside water into the bowl for flushing, as well
as pumping waste from the bowl to the holding tank. Do you have a
second pump there?

A Jabsco toilet--which is what he has--has only one dual action pump. In
the "wet" mode, it brings in flush water AND pushes bowl contents
out...in the "dry" mode, it pushes bowl contents out without bringing in
any flush water.

I would think that the only thing that can get into the holding tank
is what you pump there while flushing the head.

Since he's indicated that his bowl is filling with clean water, it's
unlikely that his holding tank is filling to overflowing and running
back toward into the bowl.

Nor is it likely that a fouled joker valve has any bearing on it.
Whizzit that everyone wants to blame the joked valve for ANY toilet
problem, even flush water intake issues???
--
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

Thanks for all the info. I am familiar with the toilet and the wet/dry
mode. That definitely isn't the issue as I move the lever to dry after
each use. Even in the dry mode, water is entering the head.

As simple as it sounds, I believe the issue is that I've been leaving
the seacock during the week when I'm not using the boat. I guess I
need to close the seacock between uses as well. This is inconvenient,
but possible as I have pretty easy access to the seacock.

I am still not sure about the second pump that I have. I will take
pictures and send, but here's a bit better explanation of if:

The pump is a hand pump similar to a manual bilge pump. It forms an
upside down "T".

1. Hose enters boat through seacock and does a loop to about 5' in the
air. This is a 2nd seacock - not the one used for water to enter the
head. It is also larger. Probably 1 1/2" hose vs. the smaller used
for the head intake.
2. It goes back to form the stick part of the T.
3. On the "across" part of the T (bottom of pump), there is flow going
from holding tank to the pump out access on the deck.

I am assuming this is used to help push the material out and to flush
the system.

Hobieshane wrote:

Thanks for all the info. I am familiar with the toilet and the wet/dry
mode. That definitely isn't the issue as I move the lever to dry after
each use. Even in the dry mode, water is entering the head.

As simple as it sounds, I believe the issue is that I've been leaving
the seacock during the week when I'm not using the boat.

It's actually two issues--open seacock AND the wet/dry cam in the pump
has failed...it's not cutting off the flow of flush water any more.
That's a VERY common problem in Jabsco toilets made in the 5-6 years,
due to either a design or tooling defect. And apparently Jabsco has no
intention of correcting it till the mold for that little part wears out.

It also provides an excellent illustration of why relying on the wet/dry
valve instead of closing the seacocks when leaving the boat is VERY
risky...'cuz while it's a common problem in Jabsco toilets, no toilet is
immune from wet/dry valve failure.

I guess I
need to close the seacock between uses as well. This is inconvenient,
but possible as I have pretty easy access to the seacock.

A vented loop in the head intake would prevent water from rising in the
bowl while the boat is at rest, but would not prevent it while the boat
is underway. So, yes...till you replace the wet dry valve--or better
yet, replace the toilet with one that's better quality--you will have to
keep the seacocks closed between uses while underway, but if you install
a loop, you could leave 'em open at the dock.

I am still not sure about the second pump that I have. I will take
pictures and send, but here's a bit better explanation of if:

The pump is a hand pump similar to a manual bilge pump. It forms an
upside down "T".

1. Hose enters boat through seacock and does a loop to about 5' in the
air. This is a 2nd seacock - not the one used for water to enter the
head. It is also larger. Probably 1 1/2" hose vs. the smaller used
for the head intake.

That's your head DISCHARGE...the hose EXITS the boat at that thru-hull.
There should be a y-valve in that line that allows you to choose between
flushing directly overboard or into the tank.

What passes for a manual for your toilet is on the Jabsco website he
http://www.jabsco.com/prodInfo/overv...UAL_TOILET.PDF
You can see a drawing and illustrations of typical installations...I
think if you compare those illustrations to what you have, what you have
will become a lot clearer.


2. It goes back to form the stick part of the T.
3. On the "across" part of the T (bottom of pump), there is flow going
from holding tank to the pump out access on the deck.
I am assuming this is used to help push the material out and to flush
the system.

None of that makes any sense...I'm gonna have to see some photos and
sketches of the plumbing runs to know what you have. What you SHOULD have:

3/4" ID hose from intake through-hull to the pump...at the back on the
bottom of the "compartment" that houses the wet/dry lever and cam.
There should be no loop in that line.

3/4" hose coming off the top of the pump to the inlet fitting on the
back of the bowl. The should be a vented loop in that line that's high
enough to be at least 6-8" above the waterline at any angle of
heel...but there may not be...it may be only a short piece of hose
between the pump and bowl.

Both the pump and the bowl rest on a cross piece called the base. It's
not a pump...the Jabsco manual only has one dual action pump.

1" or 1.5" hose off the back of the bottom of the pump that MAY go only
to a tank, or may go to a y-valve...one side of the y-valve up and over
a vented loop (same height as the intake loop) and to a thru-hull..the
other side to a fitting at or on the top of the tank.

1/5" hose coming off the tank at the bottom...it will either go directly
the deck pumpout fitting, or MAY go to either a y-valve or tee
fitting...one side to the deck pumpout fitting, the other side to a pump
(manual diaphragm...i.e. Whale Gusher, or electric macerator pump), then
up and over yet a 3rd vented loop to a thru-hull--which may be separate
from the direct toilet discharge thru-hull, or may be teed into that
line to use the same thru-hull.

If what you have is much different from that, it's plumbed incorrectly
and needs to be corrected...but I suspect that's pretty much what you
have--+/- some or all vented loops.

If you aren't sure what things like manual discharge pumps, macerators,
y-valves (aka diverter valves) and vented loops look like, do a search
for 'em on any of the marine retail sites.

--
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

It's starting to make more sense now.

First, I need to replace my wet/dry cam.

Second, It looks like I have two options for pumping out the holding
tank: 1. Through the deck fitting or 2. Through the 1.5" hose exiting
the hull next to the fresh water intake seacock.

The whale pump appears to pump from the tank, go through a vented loop,
and exit the thru-hull. What I am still confused about is that the
pump out deck hose is connected to this as well. Is it as simple as
when the thru-hull is open, the whale pumps out through it? Otherwise,
I would pump out through the deck fitting.

I do want to note to everyone that I know to not pump directly to the
lake as I am inland.