Pump it all the way to the tank??

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Tom Martin

Peggie, I spent five hours yesterday rebuilding the head in a Beneteau (to no avail), then unclogging a blocked discharge line (between the Jabsco head and the Y valve). Nasty - hope to never need to do that again! So today (in hopes of not repeating the disaster) I turned to one of your articles and read "flushing 101", and discovered that we haven't been flushing the stuff all the way to the holding tank each time. You said to determine how many strokes it takes to move the "contents" all the way to the tank, on the "dry bowl" setting (if I understood correctly), and then pump that many times every time. But it seems to me if there is, say a gallon of water etc in the head when the valve is switched to "dry", you could pump forever and not move it to the tank (at least on my boat), because the discharge hose rises (in the lazarette) about 3 feet above the head before it hits the y valve; the hose from the Y valve to the tank then dives back down to "bottom of the lazarette" level on its way to the holding tank, then climbs back up to enter the tank which is 2-3 ft above the head. The system is vented of course, so how can that gallon of water+stuff ever get pushed uphill that far? Unless there is new water being pumped into the discharge hose (wet bowl), it seems to me the "stuff" is just going to sit in the vertical hose behind the head (and gurgle around a bit as you pump..). Following this logic to its conclusion, I think that with a system like mine you will never end up with only water in the lines - the "stuff" will just get more diluted the longer you pump on wet bowl. If this is the case I guess we should just pump on wet bowl for 8-10 strokes anytime there are solids in the bowl, to at least encourage them up that hill. Sure will be pumping out the holding tank more often though. Am I missing something? I really don't want to unclog that hose again........... Thanks for your help!
 
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Peggie Hall/Head Mistress

Believe it or not,

a manual marine toilet that's working anywhere near specs CAN lift water 3' with air pressure only. Granted, it takes quite a bit of pumping, but it will do it--the operative phrase here being "working anywhere near specs." If the seals and/or the pump cylinder are worn, the resulting air leak won't let it. Your system is pretty convoluted (eventually boatbuilders MAY figure out where to put tanks...so if flushing all the way through on dry requires more pumping than anyone, especially guests, is willing to do, and pumping wet till it's all the way through the system fills up your holding tank too fast--or, if your toilet isn't capable of doing it on dry--at least move everything all the way through the system once a day to completely clear the lines. Your system clogged because everyone quit flushing as soon as the bowl was empty, letting paper and solids literally pile up in the vertical line between your toilet and the y-valve. So whether you pump the bowl contents ALL the way through with EVERY flush or not, if you want to prevent future clogs, it's essential that you flush enough each time to clear the y-valve and at least let it get started moving downhill.
 
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dave

paper

Whenever I go out on a scuba diving charter boat they always have a briefing on safety and use of the boat facilities. Every single one of them always requires NO PAPER IN THE TOILET, only materials from the human body go in there and all paper goes in a trash bag for landside disposal. Now I don't know why they do this but it seemes to make sense in terms of all the other stuff will dissolve in water whereas paper will cause the clogs and hassles you refer to. C.d
 
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dave

y-valve in discharge line???

Why do you have a y-valve in your discharge line? This is an obvious obstruction. The only reason I can think for having this is to allow direct overboard discharge of waste which is illegal unless you have a treatment system or are over three miles offshore. Doesn't it make more sense to remove the y-valve have the discharge line go directly into the tank (so all waste end up in the tank) and then the y-valve is in the tank discharge line to either go to a macerator pump for overboard discharge or to a deck fitting for boat or dockside pump out? C.d
 
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Peggie Hall/Head Mistress

Now that you mention it...

The boat is on an inland lake (something I failed to notice till you raised the question) where he can't even discharge through a treatment device, much less go directly overboard. He can't legally dump the tank either. So why IS there a y-valve in the head discharge line? However, toilet paper shouldn't cause a problem unless it's the wrong kind or too much at a time goes down the toilet. Cheap flimsy institutional grade TP dissolves faster than solid waste. Otoh, when you have guests aboard who aren't boat owners, it's easier to make a rule that NOTHING goes in the toilet than to try to explain that a marine toilet can handle *limited* amounts of the TP supplied, but facial tissue, paper towels, tampons and ANYthing else will choke it. I used to keep a little "diaper pail" and liners in my dock locker that came out for landlubber guests and went back when they left.
 
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Tom Martin

thanks for some good ideas

Thanks all for the comments - The Y valve is there because Beneteau built it that way - it's locked in position so can't discharge into the lake. Removing it may be a good idea to remove an obstruction (although it would still be an uphill trip to the tank). But Peggie I think I have to respectfully wonder about even a perfect pump moving water uphill very far with only air to push it along - bubbles go up, water falls down it would seem.
 
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Peggie Hall/Head Mistress

If the pump is holding a prime,

whether it's air or water, the air or the water will move what's ahead of it. Granted, the further it has to go, the less momentum it will have, but 3' is not unreasonable for a new toilet--or one that's still in "new" working condition--to move at least 90% of it. Follow the waste with a little flush water to get rid of the remaining 10%.
 
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