When leaving the boat I pump the head dry and leave the switch in the dry position. On return the head is half full of dirty water from the holding tank. Why is the water backing into the head? Do I need to rebuild the pump?
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One more time...
You're the 4th person in the last 24 hours to ask about the same problem. Go to "Back flow in the bowl" in this forum for the answer. Fwiw, unless a tank is full to overflowing, there's no way that any dirty water running back into the toilet can be coming from the tank. The tank inlet is at the top of the tank...waste can't jump. So the dirty water can ONLY be waste/water that's still in the head discharge hose. The wet/dry valve has no effect on toilet DISCHARGE, it only blocks or allows INCOMING flush water. So leaving it in the dry position has nothing to do with backflow. However, if you rely on the wet/dry valve instead of closing the intake seacock when you leave the boat, sooner or later you can expect to find your boat sitting on the bottom of your slip...'cuz wet/dry valves fail. Head and holding tank thru-hulls left open when no one is aboard is the #1 cause of boats sinking their slips.
You're the 4th person in the last 24 hours to ask about the same problem. Go to "Back flow in the bowl" in this forum for the answer. Fwiw, unless a tank is full to overflowing, there's no way that any dirty water running back into the toilet can be coming from the tank. The tank inlet is at the top of the tank...waste can't jump. So the dirty water can ONLY be waste/water that's still in the head discharge hose. The wet/dry valve has no effect on toilet DISCHARGE, it only blocks or allows INCOMING flush water. So leaving it in the dry position has nothing to do with backflow. However, if you rely on the wet/dry valve instead of closing the intake seacock when you leave the boat, sooner or later you can expect to find your boat sitting on the bottom of your slip...'cuz wet/dry valves fail. Head and holding tank thru-hulls left open when no one is aboard is the #1 cause of boats sinking their slips.
Pump more than the head dry
On my 35.5 it takes 15 strokes after the head is dry before water stops flowing into the holding tank. I know because I have removed the aft cabin panel and had different people pump as I listened to the water flow into the tank. Anything less than 15 strokes after the bowel is dry leaves water in the hose. I will bet you that most people don't have a clue about how many pump strokes it takes to empty the hose.
On my 35.5 it takes 15 strokes after the head is dry before water stops flowing into the holding tank. I know because I have removed the aft cabin panel and had different people pump as I listened to the water flow into the tank. Anything less than 15 strokes after the bowel is dry leaves water in the hose. I will bet you that most people don't have a clue about how many pump strokes it takes to empty the hose.
No need
to pump the whole outtake line dry if the joker valve is working correctly. That's the job of the joker valve, to stop back flow. Now if the joker valve isn't working correctly, then pumping 15 times is a temporary solution but your causing un-needed wear and tear on the pump in doing so.
to pump the whole outtake line dry if the joker valve is working correctly. That's the job of the joker valve, to stop back flow. Now if the joker valve isn't working correctly, then pumping 15 times is a temporary solution but your causing un-needed wear and tear on the pump in doing so.
Yes, there is a need, Franklin...
The inside of a hose is an aerobic environment, so waste left sitting in a hose gets very ripe...and that results in permeated hoses. It can also lead to clogs as waste piles up in the hose going into a bend. So not only should waste be pumped all the way to the tank each time, but before the boat sits, the head discharge hose should be thoroughly flushed out with clean fresh water too.
The inside of a hose is an aerobic environment, so waste left sitting in a hose gets very ripe...and that results in permeated hoses. It can also lead to clogs as waste piles up in the hose going into a bend. So not only should waste be pumped all the way to the tank each time, but before the boat sits, the head discharge hose should be thoroughly flushed out with clean fresh water too.
Backflow
Peggy: I read the previous threads about backflow and I'm convinced that I've got a clogged line and a full blackwater tank on our "new to us" Catalina. Is there a particular "safe" way to clean out the clogged hose? Can I use a regular plumber's snake? Also, where's the joker valve located? I looked on the schematics for the plumbing and I don't see it marked. Will a plumber's snake damage the valve? Finally, when we flushed the head, blackwater came out of a small hole in one of the rails on deck. Is that some sort of vent? Does it have to be cleaned out, too?
Peggy: I read the previous threads about backflow and I'm convinced that I've got a clogged line and a full blackwater tank on our "new to us" Catalina. Is there a particular "safe" way to clean out the clogged hose? Can I use a regular plumber's snake? Also, where's the joker valve located? I looked on the schematics for the plumbing and I don't see it marked. Will a plumber's snake damage the valve? Finally, when we flushed the head, blackwater came out of a small hole in one of the rails on deck. Is that some sort of vent? Does it have to be cleaned out, too?
You don't have a clog, Manolo...
You just have an overfull tank. "when we flushed the head, blackwater came out of a small hole in one of the rails on deck. Is that some sort of vent?" Yes. Waste is coming out of it because your tank is so overfull that it's overflowing. It's backing up into you toilet because it can't overflow out the vent fast enough to keep up with the volume coming into the tank from the toilet...the back pressure is pushing back when you flush. Does it have to be cleaned out, too? Unless you want it become completely blocked by waste, yes! It's essential that the vent be completely open...'cuz it has to be able to provide an escape for air in the tank displaced by waste coming into it, otherwise the tank will become pressurized--which is happening to some degree, and why your waste is backing up. The vent also has to provide a source of air to replace tank contents being sucked out when you pump out...if it can't, the pumpout will pull a vacuum that prevents waste from being sucked out, and can result in a cracked tank. The joker valve is a cup-shaped rubber thingy in the toilet discharge fitting...part # 32 on the drawing. And yes, running a snake through it will damage it...it'll stretch the slit in it. Don't use a plunger either...that'll damage the rubber parts in the pump. Do not flush the toilet again till you've pumped out the tank. And when you do pump out, watch the flow of waste in the pumpout hose sight glass to make sure waste IS being pumped out...if it's not, cease pumpout IMMEDIATELY and don't try again till you're sure the vent is open. I also strongly recommend that you go to the link below to learn how your toilet works, how to maintain the whole system properly to prevent problems, what to do--and what NOT to do--if you do have to cure any problems.
You just have an overfull tank. "when we flushed the head, blackwater came out of a small hole in one of the rails on deck. Is that some sort of vent?" Yes. Waste is coming out of it because your tank is so overfull that it's overflowing. It's backing up into you toilet because it can't overflow out the vent fast enough to keep up with the volume coming into the tank from the toilet...the back pressure is pushing back when you flush. Does it have to be cleaned out, too? Unless you want it become completely blocked by waste, yes! It's essential that the vent be completely open...'cuz it has to be able to provide an escape for air in the tank displaced by waste coming into it, otherwise the tank will become pressurized--which is happening to some degree, and why your waste is backing up. The vent also has to provide a source of air to replace tank contents being sucked out when you pump out...if it can't, the pumpout will pull a vacuum that prevents waste from being sucked out, and can result in a cracked tank. The joker valve is a cup-shaped rubber thingy in the toilet discharge fitting...part # 32 on the drawing. And yes, running a snake through it will damage it...it'll stretch the slit in it. Don't use a plunger either...that'll damage the rubber parts in the pump. Do not flush the toilet again till you've pumped out the tank. And when you do pump out, watch the flow of waste in the pumpout hose sight glass to make sure waste IS being pumped out...if it's not, cease pumpout IMMEDIATELY and don't try again till you're sure the vent is open. I also strongly recommend that you go to the link below to learn how your toilet works, how to maintain the whole system properly to prevent problems, what to do--and what NOT to do--if you do have to cure any problems.
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