Visit our Popular Forums

peghall · 26-06-2018, 12:06

A couple more questions: Are you 100% certain the water is backflow and incoming? If you are, does the toilet discharge line run uphill--for instance, to a vented loop and then back down to the tank or thru-hull?

If you're not 100% certain it's backflow, is there a vented loop with a solenoid valve in the toilet inlet?

--Peggie

Kathham · 29-06-2018, 06:57

Quote:

Originally Posted by peghall

A couple more questions: Are you 100% certain the water is backflow and incoming? If you are, does the toilet discharge line run uphill--for instance, to a vented loop and then back down to the tank or thru-hull?

If you're not 100% certain it's backflow, is there a vented loop with a solenoid valve in the toilet inlet?

--Peggie

My earlier reply did not quote your questions but I did respond. Yes, the discharge line runs uphill to a vented loop and back down to thru hull. We do not have a solenoid valve. Thanks Peggie

peghall · 29-06-2018, 09:54

I think I have enough information now to know what your problem is...actually two problems. Any backflow has to be water left in the line between the toilet and the top of the loop. Flushing longer in the "dry" would solve that problem in a manual toilet, but not much you can do about it in an electric toilet that doesn't have a "dry" option. However, that's not enough water fill the bowl...and besides, the joker valve should be reducing the flow to slow seepage.

So the real problem has to be INflow...water outside the boat is seeking it's own level INside the boat via toilet intake line. There needs a vented loop in it. If your toilet is a basic 37010 Jabsco 37010 owners manual it can be installed in the line that connects the pump to the back of the bowl, eliminating the need for the solenoid valve in it that would be necessary if it's installed where it's shown in the owners manual. However, if it's a 37045 Jabsco Quiet Flush SW model owners manual the loop has to be installed in the line between the remote inlet pump and the toilet (no solenoid valve needed here either, just be sure there's an air valve in the vented loop. (see photo) In either case, the loop needs to be at least 6-8" above waterline at any angle of heel...but since cats don't heel, I'd just aim for about 10" above waterline.

You're welcome to contact me directly with more questions...I'm always glad to help.

--Peggie

Capt Gill · 29-06-2018, 14:21

Quote:

Originally Posted by peghall

If it only happens when the boat is underway with the overboard seacock open, you may be experiencing something known as "ram water"--water being pushed ("rammed") up the toilet discharge hose by the pressure of the hull moving through the water. The same thing often happens when sink drain seacocks are open.

If it also happens when the boat is sitting at rest, water outside the boat is simply seeking its own level INside the boat. If there's no vented loop in the toilet intake, it's not backflow...the only thing preventing sea water from flooding--and overflowing--the bowl is the wet/dry cam (which, btw, is highly failure prone in Jabsco toilets). If it is backflow, a new joker valve can block it, but only temporarily until the the toilet has had enough to use to stretch the slit open even a milimeter. If there are no vented loops in the intake and discharge lines, install them. They both need to be at least 6-8" above waterline at ANY angle of heel...which, on most sailboats, puts it 2-3' above the bowl (see photo). See the drawing in the Jabsco owners manual for the correct location of the intake vented loop.

I have a similar situation, i.e., toilet bowl rim is at waterline, if someone leaves the lever at the "wet bowl" position the bowl will o'flow when heeled to port (S/B tack), but not in "dry bowl" position-so far. I have the parts to install a vacuum break for the intake (out take has break), however installing the break between the pump and the bowl does not eliminate the possibility of water ingress from the intake to the pump if the valve as you say "highly failure prone " fails and a break installed on that hose won't work as it's vacuum. The confusion is that Jabsco says any "through hull fittings".
My set up is as below attachment.
As per Jabsco:
"If the toilet is connected to ANY through-hull fittings, and if the rim of the bowl falls below the waterline, water may flood in causing the craft to sink, which may result in loss of life.
Therefore, if the rim of the toilet is less than 20cm (8") above the waterline when the craft is at rest, or if there is ANY possibility that the rim of the bowl may be below the waterline at ANY time, a ventilated anti-syphon loop MUST be fitted in any pipework connected to a through-hull fitting, irrespective of whether inlet or outlet.
USE VENTED LOOPS"

peghall · 29-06-2018, 17:37

I have the parts to install a vacuum break for the intake (out take has break), however installing the break between the pump and the bowl does not eliminate the possibility of water ingress from the intake to the pump if the valve as you say "highly failure prone " fails and a break installed on that hose won't work as it's vacuum. The confusion is that Jabsco says any "through hull fittings".

Oh dear....<sigh>...The "highly prone valve" is IN the toilet pump..hardly likely to cause a problem between the thru-hull and the pump. And only a failed hose connection or a hose that's old it splits can allow water to escape from it.

A vented loop, correctly installed, is protection against a highly failure prone wet/dry cam assembly and fallible humans accidentally leaving it in the wet position. Putting the inlet loop between the pump and the bowl does as good a job of preventing sea water from flooding the bowl as it would if installed in the line between the thru-hull and pump...but without interfering with the pump's ability to prime.

The drawing from the Jabsco site (it's also in the owners manual) clearly shows where both the intake and discharge vented loops should be installed.

--Peggie

Capt Gill · 30-06-2018, 13:38

Quote:

Originally Posted by peghall

I have the parts to install a vacuum break for the intake (out take has break), however installing the break between the pump and the bowl does not eliminate the possibility of water ingress from the intake to the pump if the valve as you say "highly failure prone " fails and a break installed on that hose won't work as it's vacuum. The confusion is that Jabsco says any "through hull fittings".

Oh dear....<sigh>...The "highly prone valve" is IN the toilet pump..hardly likely to cause a problem between the thru-hull and the pump. And only a failed hose connection or a hose that's old it splits can allow water to escape from it.

A vented loop, correctly installed, is protection against a highly failure prone wet/dry cam assembly and fallible humans accidentally leaving it in the wet position. Putting the inlet loop between the pump and the bowl does as good a job of preventing sea water from flooding the bowl as it would if installed in the line between the thru-hull and pump...but without interfering with the pump's ability to prime.

The drawing from the Jabsco site (it's also in the owners manual) clearly shows where both the intake and discharge vented loops should be installed.

--Peggie

Many thanks for help. I was concerned about where the hose from the t/hull to pump, that if the valve on top of the pump was defective it would allow water from the t/hull intake to enter the bowl. I think when it's taken apart I'll have a better idea how this works. Again, thanks, it's nice to have to have answers from a knowledgable source.

peghall · 30-06-2018, 14:59

Jack, I think you might find my book (see link in my signature) helpful in understanding how the toilet works. The title (my publisher's idea) is a bit misleading. Although it does deal with all the sources of odor on a boat and how to eliminate/prevent 'em, it's actually a comprehensive "marine sanitation system including toilets, plumbing and holding tanks 101" manual. You can see the entire table of contents on the listing. And I'm always glad to answer any questions it doesn't.

--Peggie

**a64pilot** · 30-06-2018, 19:34

Looking at all those pretty pictures with that pretty vinyl hose makes me almost cry.
You may want to consider scheduling a time to replace them, before they begin to stink.
How long before that type of hose permeates?

jbinbi · 06-08-2018, 07:44

Update on this thread. Still have backflow even though I had replaced both joker valves. Opened cap for pumpout ro make sure it is not from clogged vent. With nothing in the tank, opened discharge while sailing, still getting yellow disgusting water filling bowl to level of pump lines. I have not replaced base gasket valve flapper. If I close water intake, there is only a small amount of clear water in bowl after pumping bowl dry, assuming this is what is in line draing back.

Also, with valves open, after pulling in lots of sea water, flushing it out, then pumping dry, after a few minutes the bowl starts burbling and bubbling and you hear the air then water comes in.

I will replace base gasket flapper, not sure what else this can be.

Empty Pockets · 06-08-2018, 07:48

The gasket flapper will fix it

IdoraKeeper · 06-08-2018, 08:14

After reading all the horror stories about joker valves, I installed a ball valve on the output of the head.. Jokers still in there, don't know if they work and it doesn't matter.:-)

jbinbi · 13-08-2018, 06:48

As an update to this thread, this weekend I replaced the base valve gasket. Also, I did not mention that I have the 'twist and lock' version of the toilet. So besides replacing the gasket flapper, I started locking the handle after emptying the bowl, leaving the lever in the 'empty' position.

So far, no water coming back.

Next to try, not locking the handle, as I have not locked the handle over the past 2 years of having the boat with the new equipment and not having backflow.

Chirinika · 05-08-2020, 09:44

Quote:

Originally Posted by Capt Gill

I have a similar situation, i.e., toilet bowl rim is at waterline, if someone leaves the lever at the "wet bowl" position the bowl will o'flow when heeled to port (S/B tack), but not in "dry bowl" position-so far. I have the parts to install a vacuum break for the intake (out take has break), however installing the break between the pump and the bowl does not eliminate the possibility of water ingress from the intake to the pump if the valve as you say "highly failure prone " fails and a break installed on that hose won't work as it's vacuum. The confusion is that Jabsco says any "through hull fittings".
My set up is as below attachment.
As per Jabsco:
"If the toilet is connected to ANY through-hull fittings, and if the rim of the bowl falls below the waterline, water may flood in causing the craft to sink, which may result in loss of life.
Therefore, if the rim of the toilet is less than 20cm (8") above the waterline when the craft is at rest, or if there is ANY possibility that the rim of the bowl may be below the waterline at ANY time, a ventilated anti-syphon loop MUST be fitted in any pipework connected to a through-hull fitting, irrespective of whether inlet or outlet.
USE VENTED LOOPS"

So if I install the vent on hose from pump to toilet bowl, will I get oder in the head compartment?