Noeta wrote:

Have a question about my head:

I have a Groco HF in my Catalina 34. It fills when the through hull
is left on.

I've rebuilt the head. Also installed new hoses and an anti-siphon
valve. The system is set up: Through hull intake to pump to Siphon
valve to bowl.

How high above the bowl is the vented loop (anti-siphon valve)?

Does the bowl fill at the dock or an anchor when the boat is at rest, or
only when underway on the same tack as the intake thru-hull?

Still, the bowl fills if the switch is left in the flush position. I
thought a an anti siphon valve would stop that.

What am I missing here?

I'll know when I have the answers to those questions.


--
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://shop.sailboatowners.com/books...ku=90&cat=1304

Peggie- Thanks for the reply and thanks for being so accessable. Here's
your questions and my answers:

" How high above the bowl is the vented loop (anti-siphon valve)?"

Approx 18"

"Does the bowl fill at the dock or an anchor when the boat is at rest, or
only when underway on the same tack as the intake thru-hull?"

Fills at the dock.




"Peggie Hall" wrote in message
om...
Noeta wrote:

Have a question about my head:

I have a Groco HF in my Catalina 34. It fills when the through hull
is left on.

I've rebuilt the head. Also installed new hoses and an anti-siphon
valve. The system is set up: Through hull intake to pump to Siphon
valve to bowl.

How high above the bowl is the vented loop (anti-siphon valve)?

Does the bowl fill at the dock or an anchor when the boat is at rest, or
only when underway on the same tack as the intake thru-hull?

Still, the bowl fills if the switch is left in the flush position. I
thought a an anti siphon valve would stop that.

What am I missing here?

I'll know when I have the answers to those questions.


--
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://shop.sailboatowners.com/books...ku=90&cat=1304

Noeta wrote:

" How high above the bowl is the vented loop (anti-siphon valve)?"

Approx 18"

"Does the bowl fill at the dock or an anchor when the boat is at rest, or
only when underway on the same tack as the intake thru-hull?"

Fills at the dock.

Your loop isn't high enough...it needs to be at least 6-8" above the
waterline at ANY angle of heel...which on most sailboats puts it at
least shoulder high. When the bowl is below waterline--which I'm 99%
certain yours has to be--a loop that's only 18" above it is low enough
that any wake or wave action will push water over the top of it.

And, there's another possibility: priming a manual toilet starts a
siphon...the vented loop is supposed to allow air into the line to break
it. But if you put a vent tube on it instead of an air valve, it can
very quickly become blocked with sea water minerals...turning the loop
into an UNvented loop that no longer has any ability to break a siphon.
If there is an air valve, it may be defective or clogged...they do
require periodic cleaning and replacement. If there's no air valve OR
vent tube coming off the top, and it doesn't squirt water when you pump
the toilet in the "flush" mode, your vented loop isn't vented (it's
either clogged or defective), so it's not breaking the siphon started by
flushing.

But whatever else may be going on, you definitely need to raise the loop
to the right height. If that doesn't solve your problem, I suspect
there's a problem with the vented loop.

Peggie

"Peggie Hall" wrote in message
om...

Noeta wrote:


Have a question about my head:

I have a Groco HF in my Catalina 34. It fills when the through hull
is left on.

I've rebuilt the head. Also installed new hoses and an anti-siphon
valve. The system is set up: Through hull intake to pump to Siphon
valve to bowl.

How high above the bowl is the vented loop (anti-siphon valve)?

Does the bowl fill at the dock or an anchor when the boat is at rest, or
only when underway on the same tack as the intake thru-hull?

Still, the bowl fills if the switch is left in the flush position. I
thought a an anti siphon valve would stop that.

What am I missing here?

I'll know when I have the answers to those questions.


--
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://shop.sailboatowners.com/books...ku=90&cat=1304



--
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://shop.sailboatowners.com/books...ku=90&cat=1304

"Peggie Hall" wrote in message
t...
Noeta wrote:

" How high above the bowl is the vented loop (anti-siphon valve)?"

Approx 18"

"Does the bowl fill at the dock or an anchor when the boat is at rest,
or
only when underway on the same tack as the intake thru-hull?"

Fills at the dock.

Your loop isn't high enough...it needs to be at least 6-8" above the
waterline at ANY angle of heel...which on most sailboats puts it at
least shoulder high. When the bowl is below waterline--which I'm 99%
certain yours has to be--a loop that's only 18" above it is low enough
that any wake or wave action will push water over the top of it.

And, there's another possibility: priming a manual toilet starts a
siphon...the vented loop is supposed to allow air into the line to break
it. But if you put a vent tube on it instead of an air valve, it can
very quickly become blocked with sea water minerals...turning the loop
into an UNvented loop that no longer has any ability to break a siphon.
If there is an air valve, it may be defective or clogged...they do
require periodic cleaning and replacement. If there's no air valve OR
vent tube coming off the top, and it doesn't squirt water when you pump
the toilet in the "flush" mode, your vented loop isn't vented (it's
either clogged or defective), so it's not breaking the siphon started by
flushing.

But whatever else may be going on, you definitely need to raise the loop
to the right height. If that doesn't solve your problem, I suspect
there's a problem with the vented loop.

Peggie

"Peggie Hall" wrote in message
om...

Noeta wrote:


Have a question about my head:

I have a Groco HF in my Catalina 34. It fills when the through hull
is left on.

I've rebuilt the head. Also installed new hoses and an anti-siphon
valve. The system is set up: Through hull intake to pump to Siphon
valve to bowl.

How high above the bowl is the vented loop (anti-siphon valve)?

Does the bowl fill at the dock or an anchor when the boat is at rest, or
only when underway on the same tack as the intake thru-hull?

Still, the bowl fills if the switch is left in the flush position. I
thought a an anti siphon valve would stop that.

What am I missing here?

I'll know when I have the answers to those questions.


--
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://shop.sailboatowners.com/books...ku=90&cat=1304



--
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://shop.sailboatowners.com/books...ku=90&cat=1304


Changed a few things (raised the vent a bit) and it still does not work.

The bowl is roughly at the water line, and the loop/ vent is 25" above that.
Still floods.

I've tried removing the valve entirely and creating a hole in the loop after
flushing and it still siphons. Also tried it with the through hull outlet
closed to make sure it wasn't coming in that way.

The waste line had a pre- existing loop in the same area. Now I'm thinking
if the water loop doesn't work the waste vent won't work either.

Noeta wrote:
Changed a few things (raised the vent a bit) and it still does not work.

The bowl is roughly at the water line, and the loop/ vent is 25" above that.
Still floods.

I've tried removing the valve entirely and creating a hole in the loop after
flushing and it still siphons.

Damn! That means it HAS to be a siphon...something has to pulling it to
create the siphon, 'cuz there's no way that water can flow over a loop
25" above waterline passively...water doesn't run uphill! But even so,
why isn't the air break in the vented loop breaking it?

I'm gonna forward this whole thread to a couple of my gurus...'cuz I'm
stumped!

Also tried it with the through hull outlet
closed to make sure it wasn't coming in that way.

I wondered if the intake was actually the source. Is your tank filling
up when the intake seacock is closed?

The waste line had a pre- existing loop in the same area. Now I'm thinking
if the water loop doesn't work the waste vent won't work either.

Let's not worry about that one till we solve this problem.


--
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://shop.sailboatowners.com/books...ku=90&cat=1304