Backflow

Peggie Hall HeadMistress · Jul 14, 2007

Not a toilet failure...

The problem is downstream of the toilet. If you aren't feeling any backpressure when you pump the toilet, I suspect you aren't flushing long enough in the dry mode to get it all the way into the tank. However, it IS time to replace the joker valve in the toilet. That won't cure your problem, but it will take a lot longer for the waste in the hose to seep back into the bowl. Till it became worn enough to allow more than very slow seepage, it would mask the fact that you aren't pumping the toilet long enough in the dry mode to get the bowl contents all the way into the tank. Or the tank is full...the flush has nowhere to go but back into the toilet. If you've pumped out recently, make SURE the vent line--both ends of it, the thru-hull and the connection to the tank--is completely clear...'cuz it's very possible that your tank vent is just barely open enough to allow enough air in the tank to escape between toilet uses to keep the tank from staying pressurized enough for you to feel it when you pump, but not enough to prevent a pumpout from pulling a vacuum...'cuz that hissing gurgling sound is an indication of backpressure. And unless enough the pumpout can pull enough air through it to prevent it pulling a vacuum, it prob'ly only pulled out a gallon or two.

Peggie Hall HeadMistress · Jul 14, 2007

You didn't actually solve the problem at all...

You only put a "band aid" on it. There has to be waste in the hose to flow back into the toilet. So while replacing the joker valve will prevent it from getting all the way into the bowl--at least for a while, it won't magically send the waste you're leaving in the head discharge line into the tank...it'll still be sitting in the hose to permeate it. And will start seeping into the bowl again once the new joker valve starts to become a little worn.So changing the joker valve didn't actually solve the problem at all...it only lets you get away with leaving waste sitting in hose. The REAL solution: pump the toilet long enough in the dry mode to move the bowl contents all the way to the tank so there won't be any left sitting in the line to permeate and run bsck to the toilet.

BobW · Jul 14, 2007

As Peggy pointed out....

There is obviously 'waste water' remaining in your hose after you pump. The joker valve is not designed to prevent this waste water from seeping back into the bowl - that's NOT its designed function. Yes, a new joker valve will 'seal' the hose and give you the impression that you have solved your problem..... until it too starts seeping, which will happen just as soon as crud starts growing between its 'lips' and lets the water seep through.Do you have a vented loop between the pump and holding tank? Almost all sailboats need one - yours included, probably.Your basic problem is that your pump isn't clearing the line - pumping the waste water either all the way to the tank (where it will fall in) or over the top of the vented loop.The culprit is either the 0-ring on the pump cylinder or, more likely, the flapper valve at the bottom of the pump. This valve opens up on the pump up-stroke to let water (and whatever else that's in the bowl) into the pump body, then closes on the down-stroke to direct the water to the output hose.Any damage to this valve will prevent it from sealing correctly, with a corresponding loss of pressure on the down-stroke. If you are brave enough to peer into the toilet bowl during the down-stroke (I'm reminded of the time I spent on nuclear subs where the sewage system was purged with VERY high pressure air, and anyone who disregarded the warning signs and flushed during this process got a 'brown' shower *yks), ANY 'backflow' you see after the bowl has been emptied and you are trying to move the waste water to the tank is an indication that the flapper valve isn't sealing correctly.You can replace the flapper valve, but unfortunately, it isn't very well built OR designed. Rather than buying a joker valve each year, just bite the bullet and buy the whole service kit ($60 from WM), which contains the joker valve, flapper valve, 0-rings for the pump shaft and a bunch of other stuff you probably won't need.OR, bite the BIGGER bullet and buy a REAL toilet.BTW, I'm AMAZED at how many expensive, brand-new boats I see, either in person or on YachtWorld, that have this cheap, poorly designed Jabsco toilet!Cheers,Bobs/y X Sail R 8

Peggie Hall HeadMistress · Jul 15, 2007

All true, Bob...but you're overlooking one thing

Any toilet, even a Jabsco, that's working anywhere NEAR factory spec can move bowl contents up to 4 vertical feet and 6 linear feet in the dry mode. But 99% of people don't know how to use a marine toilet correctly--they stop pumping the minute the bowl is empty, and never use the "dry" mode except to push the last bit of water out of the bowl. So it wouldn't matter what condition the flapper valve is in, or whether the toilet is good quality or a piece of junk....unless they learn to pump it long enough in the dry mode to move the bowl contents all the way to the tank or over the top of a loop, they're still gonna leave bowl contents sitting in the head discharge hose to run back into the toilet...and continue to believe that replacing the joker valve is the solution.

Jim Rushing · Jul 15, 2007

Count the strokes

On my Hunter 35.5 it took 15 strokes of the pump to move the contents of the entire bowel to the tank. Anything less than 15 would leave something in the line and guess where the lowest point was in the line. Fill your bowel full of water and have somebody pump it out and count the strokes out loud. Put your ear close enough to your holding tank to hear the water splashing in. When it stops splashing, remember the number of strokes that it took to do that and add one more. Post a notice next to the head that states what the minimum number of strokes is needed each time you flush.

Peggie Hall HeadMistress · Jul 15, 2007

And do it while pumping in the DRY mode...

One of the reasons why people don't pump long enough is because they don't want to fill up their tank with flush water...it's never occurred to 'em that the dry mode will move waste. So learning how to use the dry mode solves TWO problems: gets rid of waste left to sit in the line and can double or even triple the number of flushes a tank can hold. Jim, I'm trying to decide whether your mispelling of "bowl" as bowel" is just a typo or a Freudian slip.

Jim Rushing · Jul 15, 2007

Beats Me Peggy

Darn spell checker doesn't seem to work. My new boat is a Catalina 387 with the electric head. I never know how long to push the button. It is pumping up to a tank that is almost right behind the head. The verticle lift is about 4 feet. And it is a little bitty tank, so you really don't want to waste capacity.

BobW · Jul 15, 2007

Flapper valves and joker valves.....

I agree with you, Peggy, that a toilet pump in good condition should push the water over the vented loop and all the way to the tank.The problem here is that if the flapper valve is warped or damaged in ANY way, or if something solid from the bowl prevents it from sealing correctly on the down-stroke, the pump will not develop all the pressure it is capable - some of the pressure gets diverted back towards the bowl instead of 100% of it going out the output to the tank. It doesn't take much decrease in pressure to inhibit the pump's ability to overcome the vented loop height.Also, this is where the primary purpose of the joker valve comes in - on the up-stroke, it's 'duck-bill' 'lips' squeeze shut, so the pump takes in the bowl contents, rather than what is already in the output hose. After the bowl is emptied, the joker valve makes sure the pump sucks in AIR on the up-stroke, rather than just pumping the contents of the output hose back and forth.So, TN, pump a lot more in dry mode after the bowl is empty - if you STILL can't get the output hose evacuated, you need to pull your pump apart again and probably replace the flapper valve.Cheers,Bobs/y X SAIL R 8