Wastewater backflow from the holding tank into the bowl when sailing. This is a kind of stinky problem. I have the toilet repair kits, is there anything special to look out for repairing it? Thanks Jim
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The cure
The problem isn't in the toilet. When the tank inlet is in the wrong place (next to the hull instead of toward the centerline), heeling can send even a half-full tank back into the head discharge hose. Replacing the joker valve in the toilet will prevent it only temporarily...till the toilet has been used enough times to stretch the slit open even a little. The cure is a vented loop in the head discharge hose that's at least 8-12" above the waterline at any angle of heel--an "arch" in the line that's too high for the waste to climb over. The easiest place to put it is immediately after the toilet, mounted on a bulkhead behind the toilet. If your toilet has a straight fitting, call the mfr for a 90 degree replacement. Take the head discharge hose straight up to vented loop, back down to an inline 90 degree radius fitting that connects to the section of hose going to the tank.
The problem isn't in the toilet. When the tank inlet is in the wrong place (next to the hull instead of toward the centerline), heeling can send even a half-full tank back into the head discharge hose. Replacing the joker valve in the toilet will prevent it only temporarily...till the toilet has been used enough times to stretch the slit open even a little. The cure is a vented loop in the head discharge hose that's at least 8-12" above the waterline at any angle of heel--an "arch" in the line that's too high for the waste to climb over. The easiest place to put it is immediately after the toilet, mounted on a bulkhead behind the toilet. If your toilet has a straight fitting, call the mfr for a 90 degree replacement. Take the head discharge hose straight up to vented loop, back down to an inline 90 degree radius fitting that connects to the section of hose going to the tank.
Have the tank and hoses empty
or as empty as possible, if you can still flush, get the lines clear or at least so that the standing water is clean. You will get some back flow from anything standing in the lines. Over all, not too big a job, I think you will be surprised at how easy it is to rebuild the pump. Watch out for the plunger rod, if it has a clip to hold the plunger piece on, then Jabsco offers to replace it with a new piece, I can't recall if this was info in the rebuild kit, or if this info was provided on this site. I found out about it after I had rebuilt the unit and the plunger broke. Good luck. Bruce Neon Moon
or as empty as possible, if you can still flush, get the lines clear or at least so that the standing water is clean. You will get some back flow from anything standing in the lines. Over all, not too big a job, I think you will be surprised at how easy it is to rebuild the pump. Watch out for the plunger rod, if it has a clip to hold the plunger piece on, then Jabsco offers to replace it with a new piece, I can't recall if this was info in the rebuild kit, or if this info was provided on this site. I found out about it after I had rebuilt the unit and the plunger broke. Good luck. Bruce Neon Moon
Let's apply a little logic., Bruce..
Backflow from an overflowing tank runs straight down the head discharge hose into the bowl through the bottom of the pump cylinder. The only thing that prevents it from being a totally open path is the joker valve in the head discharge fitting. So how can rebuilding the pump cure the problem? As I said in my reply to Jim, replacing the joker valve--which is one of the parts in a rebuild kit--WILL cure the problem temporarily...but only until the toilet has been flushed enough enough times to stretch the duckbill "lips" in the valve even a tiny bit--a couple dozen flushes at most. It'll still prevent a flood, but it won't prevent seepage (it's not supposed to...it's only supposed to prevent a flood) if you stay on the same tack long enough with a hose full of water or waste. So if rebuilding the toilet solved your problem, it's only because a new joker valve was included in the rebuild kit...and the "cure" will only last until the joker valve becomes slightly worn. You can keep applying "band aids" to the problem by replacing the joker valve once or twice a year...or you can solve it permanently with a loop in the head discharge line. The BEST "cure" for the problem is prevention: tank vent and inlet fittings closest to the centerline of the boat instead of closest to the hull. When the fittings are toward the centerline, waste flows away from the hoses when the boat is heeled in one direction...would have to flow uphill to reach the vent or inlet hoses when heeled to the other side. It's such a simple concept that you'd THINK boat builders and yards could have figured that out by now...but so far they haven't.
Backflow from an overflowing tank runs straight down the head discharge hose into the bowl through the bottom of the pump cylinder. The only thing that prevents it from being a totally open path is the joker valve in the head discharge fitting. So how can rebuilding the pump cure the problem? As I said in my reply to Jim, replacing the joker valve--which is one of the parts in a rebuild kit--WILL cure the problem temporarily...but only until the toilet has been flushed enough enough times to stretch the duckbill "lips" in the valve even a tiny bit--a couple dozen flushes at most. It'll still prevent a flood, but it won't prevent seepage (it's not supposed to...it's only supposed to prevent a flood) if you stay on the same tack long enough with a hose full of water or waste. So if rebuilding the toilet solved your problem, it's only because a new joker valve was included in the rebuild kit...and the "cure" will only last until the joker valve becomes slightly worn. You can keep applying "band aids" to the problem by replacing the joker valve once or twice a year...or you can solve it permanently with a loop in the head discharge line. The BEST "cure" for the problem is prevention: tank vent and inlet fittings closest to the centerline of the boat instead of closest to the hull. When the fittings are toward the centerline, waste flows away from the hoses when the boat is heeled in one direction...would have to flow uphill to reach the vent or inlet hoses when heeled to the other side. It's such a simple concept that you'd THINK boat builders and yards could have figured that out by now...but so far they haven't.
Thanks
Peggie, everything seems to be one big pain since I moved up from my San Jaun 21. Just thinking of the day of just sailing away with my porti-potty and outboard. So I can't mount the hose on the bulkhead behind the bathroom because it is the aft cabin. I guess it has to be mounted in the head behind the tolit. I agree with you this is a design problem. I do think that replacing the joker value would work for a little while. Maybe a few year, but I do have to go alot so looks like I'll give it a try this winter on the hard. The same type of setup is used if you use fresh water for flush with, RIGHT? I do! I am wondering should should I run both line at the ame time, one above the other? Thanks to both you and Bruce! Jim, DownTime H28
Peggie, everything seems to be one big pain since I moved up from my San Jaun 21. Just thinking of the day of just sailing away with my porti-potty and outboard. So I can't mount the hose on the bulkhead behind the bathroom because it is the aft cabin. I guess it has to be mounted in the head behind the tolit. I agree with you this is a design problem. I do think that replacing the joker value would work for a little while. Maybe a few year, but I do have to go alot so looks like I'll give it a try this winter on the hard. The same type of setup is used if you use fresh water for flush with, RIGHT? I do! I am wondering should should I run both line at the ame time, one above the other? Thanks to both you and Bruce! Jim, DownTime H28
Intake loop not needed with fresh water flush
The only reason for a vented loop in the head intake is to prevent water outside the boat from using the intake line to seek its own level inside the boat when the toilet bowl is below the waterline. Since your toilet is connected to the onboard pressurized water supply instead of a thru-hull below the waterline, that can't happen...so there's no need for a loop in the intake. If your tank fittings were in the right location, you wouldn't need one in the discharge either unless any part of the system is connected to a below-waterline thru-hull. Typically, the loop in the head discharge line is IN the head, above the toilet. But as long as it creates a "hill" higher than backflow from the tank can climb over when you're heeled, it really doesn't matter where you put it. You won't fill up your holding tank as fast if you use the lee rail as often as possible. Why the lee rail? You'll find out if you use the windward side.
Big boats have a LOT more systems than small boats. Just remember that nothing on a boat is a "stand alone" device...everything is a component of a complete system, and anything you do (or fail to do) to one part of the system impacts the whole system--and sometimes more than one system. Since you're new at this, you'll prob'ly find the articles in the Head Mistress forum reference library useful when it comes to sorting out the plumbing systems. Just click on the link to it on the forum homepage.
The only reason for a vented loop in the head intake is to prevent water outside the boat from using the intake line to seek its own level inside the boat when the toilet bowl is below the waterline. Since your toilet is connected to the onboard pressurized water supply instead of a thru-hull below the waterline, that can't happen...so there's no need for a loop in the intake. If your tank fittings were in the right location, you wouldn't need one in the discharge either unless any part of the system is connected to a below-waterline thru-hull. Typically, the loop in the head discharge line is IN the head, above the toilet. But as long as it creates a "hill" higher than backflow from the tank can climb over when you're heeled, it really doesn't matter where you put it. You won't fill up your holding tank as fast if you use the lee rail as often as possible. Why the lee rail? You'll find out if you use the windward side.
Big boats have a LOT more systems than small boats. Just remember that nothing on a boat is a "stand alone" device...everything is a component of a complete system, and anything you do (or fail to do) to one part of the system impacts the whole system--and sometimes more than one system. Since you're new at this, you'll prob'ly find the articles in the Head Mistress forum reference library useful when it comes to sorting out the plumbing systems. Just click on the link to it on the forum homepage.Try Again Peggy -- RE: Vented Loop
With a pressurized FRESH water flush feed the vented loop is an EXCELENT idea. Why you ask? I'm glad you asked! It can prevent cross contamination of the fresh water by black water. In the majority of toilet pumps thew flush water and black water are separated only by a tiny seal, usualy an "O" ring or flat rubber seal. There is always "stuff" going back and forth between the two chambers of the pump due to the inevetable "blow-by" past the seal. (I don't even want to think about what happens when the check valve on the flush water side of the pump malfunctions on a fresh water supplied system.) The vent in the supply loop breaks the path back to the tank and minimizes the likelihood of bacteria working back into the supply. This is called a vacuum breaker and is required in a surprising number of plumbing situations; IE: slop sinks, sillcock hose bibs and the like. Not a bad idea at all if you insist on feeding storred fresh water to your marine tiolet
With a pressurized FRESH water flush feed the vented loop is an EXCELENT idea. Why you ask? I'm glad you asked! It can prevent cross contamination of the fresh water by black water. In the majority of toilet pumps thew flush water and black water are separated only by a tiny seal, usualy an "O" ring or flat rubber seal. There is always "stuff" going back and forth between the two chambers of the pump due to the inevetable "blow-by" past the seal. (I don't even want to think about what happens when the check valve on the flush water side of the pump malfunctions on a fresh water supplied system.) The vent in the supply loop breaks the path back to the tank and minimizes the likelihood of bacteria working back into the supply. This is called a vacuum breaker and is required in a surprising number of plumbing situations; IE: slop sinks, sillcock hose bibs and the like. Not a bad idea at all if you insist on feeding storred fresh water to your marine tiolet
Sam...sigh...
Toilets designed to use pressurized flush water already have the necessary siphon breaks and one-way valves installed...so there's no need to install another one. They don't work the same way as toilets that aren't designed to use pressurized water, so your concerns are moot. Toilets that aren't designed to use pressurized water should never be connected to the onboard fresh water supply, 'cuz there's no way to do it without risk of contaminating the fresh water, damaging the toilet, or both. Nice try, though
Toilets designed to use pressurized flush water already have the necessary siphon breaks and one-way valves installed...so there's no need to install another one. They don't work the same way as toilets that aren't designed to use pressurized water, so your concerns are moot. Toilets that aren't designed to use pressurized water should never be connected to the onboard fresh water supply, 'cuz there's no way to do it without risk of contaminating the fresh water, damaging the toilet, or both. Nice try, though
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