No faulty pump. On our boats it is darned close, if not under the waterline. Must be different than yours because we have our aft heads, lower in the water than your forward head. Betcha that's why.
Toilet bowl unwanted filling
- Thread starter JosefR
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Jim, your statements are not very clear, perhaps because of your use of the phrase "vented loops only work if...."
If you are trying to explain how a vented loop works, fine. I got it, already knew that.
By the way, once the loop is vented, the up hill line drains, too!
For the C36 "Mk. I," it only remains to determine if the bowl is above the water line, and by how much. I'm sure someone had figure this out before. I'll bet that the pump inlet is also above the waterline. At all angles of heel? Don't now, maybe not.
If you are trying to explain how a vented loop works, fine. I got it, already knew that.
By the way, once the loop is vented, the up hill line drains, too!
For the C36 "Mk. I," it only remains to determine if the bowl is above the water line, and by how much. I'm sure someone had figure this out before. I'll bet that the pump inlet is also above the waterline. At all angles of heel? Don't now, maybe not.
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Back flow is an indication that the tank vent is blocked, causing the system to become pressurized which creates the back pressure that's sending flushes back to the toilet. If it also happens when the y-valve is set to flush directly overboard, the thru-hull may be blocke by sea life that's set up housekeeping on it or a malfunctioning seacock that isn't opening it, a malfunctioning y-valve, or a blockage in the toilet discharge line--sea water mineral buildup or a clog (a guest flushed a wet-wipe maybe?)
Whatever is causing the problem, it's essential that it be fixed 'cuz continuing to use the toilet is only gonna cause additional problems you do NOT want to happen!
The tank vent is not blocked, it blows clear when pumping out the blackwater tank at the marina. The diverter valve is brand new and working perfectly. The only thru-hulls involved have to be clear because I've been flushing gallons of water though it all weekend. The toilet discharge line is brand new, as are all the sanitation hoses. Water flows fine in all directions, there are no obstructions.
You've prob'ly answered this question in an earlier post, but....is it is an uphill run from your toilet to your tank?
Whether it is or not, have your removed the toilet discharge fitting to check the joker valve and also the inside of the discharge hose for sea water mineral buildup? Left untended, that can reduce the diameter of the hose enough to create some back pressure. In warm waters it it doesn't take long. The attached photo was posted either here or on one of the other sites I monitor a couple of years ago by a Catalina owner. Those hoses are 1.5" and smaller.
Whether it is or not, have your removed the toilet discharge fitting to check the joker valve and also the inside of the discharge hose for sea water mineral buildup? Left untended, that can reduce the diameter of the hose enough to create some back pressure. In warm waters it it doesn't take long. The attached photo was posted either here or on one of the other sites I monitor a couple of years ago by a Catalina owner. Those hoses are 1.5" and smaller.
Look on page 2 drawing from this linked manual for Jabsco but it applies to the WC drawing. It is the one that shows if anyone NEEDS a vented loop or not. Remove the vented top (called a siphon breaker in the industry) and you have a SEAL LOOP.
I was responding to the confusing info the terms on SIPHONS and when you need to have a VENTED LOOP.
@jviss your set up is like mine [HOLD TANK lower than Bowl]. We have a SEAL LOOP ( no vent needed) to help reduce hold tank back flow if your are in heavy seas with a FORE/AFT boat moves. In our set up, with the hold tank vent open, we have a no siphon and the JOKER keeps the "slosh back" from being a problem. The empty bowl stops the Froward siphon.
No way to siphon back from the HOLD TANK which is LOWER than the Bowl.Jim...
Im gonna change the joker valve in 2 weeks when I go back, but the hose is new. The old hose looked new as well, it had no buildup in it, and it looked old and was stiff as hell.
Now the hose does go upward from the bottom of the pump to the diverter valve. It goes up a little more now that I've replaced all the hoses because I couldn't see the diverter valve where it was before, in the locker. So now it's about 3 inches higher. And then it has a very tight bend to the thru-hull. About 4 feet in total. I doubt there is a bowl worth of water from the highest point of the hose to the bottom of the tank. But I'll find out when I pull the hose off to get to the joker valve.
I don't know if I have the vented loop, I can't see back there, but that sure looks like 15' of crooks and bends for crap to get clogged up in.
Now the hose does go upward from the bottom of the pump to the diverter valve. It goes up a little more now that I've replaced all the hoses because I couldn't see the diverter valve where it was before, in the locker. So now it's about 3 inches higher. And then it has a very tight bend to the thru-hull. About 4 feet in total. I doubt there is a bowl worth of water from the highest point of the hose to the bottom of the tank. But I'll find out when I pull the hose off to get to the joker valve.
I don't know if I have the vented loop, I can't see back there, but that sure looks like 15' of crooks and bends for crap to get clogged up in.
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The 'vented top' in the top of a vented loop is a nipple with a threaded hole in it that's molded into the loop, into which an air valve is installed. The air valve is replaceable, the nipple isn't. So unless you put a plug in the nipple, there's no way to turn a vented loop into a sealed loop. No one makes such a plug.
The photo is one example of an air valve in a vented loop.
The air valve opens to let air into a line when liquid is being PULLED through it...that's how it breaks a siphon. It remains closed when liquid is being PUSHED through the line to prevent water from squirting out the top of the loop. Which explains why the vented loop has to be installed between the pump and the bowl...if it's between the thru-hull and the pump, it interferes with the pump's ability to prime, When installed on electric toilets that don't have a line connecting the pump to the bowl, an electric solenoid air valve that's connected to the flush button must be installed. The solenoid closes the air valve when the flush button is operated, opens it when the flush button is released.
That was from our Catalina 34 forum. Thanks for reposting it, Peggie.
Aha...I think we may be finally getting somewhere. If you're only pumping in the wet mode to flush, all the water in the line between the toilet and the top of y-valve--maybe even all the way to the tank if the run from the y-valve doesn't run downhill-- is running back into the bowl. That line, even as far as the y-valve, holds more than you think it can. If the water is dirty, you're not pumping long enough to push the bowl contents far enough...if it's clean it's the "rinse" water behind the flush that's running back down. Earlier in this thread, I described how to use the "dry" mode to move the bowl contents to the tank--even over a loop--and then switch to "wet" to bring in some rinse water, then switch back to "dry" to pump that to the tank. Replace your joker valve, then try that and report back.
The photo I uploaed to post #2 in this shows where to put them...there's only 2-3' of line to each side of each loop.
I missed the part where you said replace it annually, so I guess we've been agreeing the whole time on what my problem is, I just hadn't seen you say it.
As for the dry mode, it looks like you're just saying pump a bunch with no water and if the joker valve isn't leaking, that should blow the hose contents past the diverter valve, no matter which direction I have it turned to.
As for the dry mode, it looks like you're just saying pump a bunch with no water and if the joker valve isn't leaking, that should blow the hose contents past the diverter valve, no matter which direction I have it turned to.
She said it and you missed it.
Except for jviss' way old WC manual (!!!), every single manual head vendor posts instructions on how to do this right. Peggie is simply trying to explain it after you misrepresent what she says .
Yeah, I missed a paragraph in a very long thread. I said I understood it and agreed with her. I asked from the beginning, I need to replace my joker valve. And I haven't misrepresented anything. Too bad you didn't show up earlier to tell me what I left out.
Sorry if I ruffled some feathers.
But seriously, as an avid reader (and sometimes contributor) here, this stuff is nothing new. The manuals all have it and Peggie, literally, wrote the book. And this same subject comes up almost every week.
Can't remember how many times I've seen "RTFM" 'cuz it's all there.
Sorry, but again, it was on page 1.
Good luck.
But seriously, as an avid reader (and sometimes contributor) here, this stuff is nothing new. The manuals all have it and Peggie, literally, wrote the book. And this same subject comes up almost every week.
Can't remember how many times I've seen "RTFM" 'cuz it's all there.
Sorry, but again, it was on page 1.
Good luck.
Yeah, it was on page one and I said I didn't see it.
Since the answer to the question "Is my joker valve on the bottom of the pump bad on a year old pump?" was YES, was it really necessary to post all of this and not actually say YES? The answer to my question was YES, not all of the following, so sorry I missed it while I was trying to sail the boat.
Since the answer to the question "Is my joker valve on the bottom of the pump bad on a year old pump?" was YES, was it really necessary to post all of this and not actually say YES? The answer to my question was YES, not all of the following, so sorry I missed it while I was trying to sail the boat.
"Let's address the overboard side first: If your toilet is below waterline, sea water is rising in the bowl to the waterline. The solution: a vented loop in the toilet discharge line that's at least 6-8" above waterline at max heel, not just when the boat is at rest...which puts about 2-3 FEET above the bowl on most sailboats. Put it immediately after the toilet...iow, aim the discharge fitting straight up. That requires a 90 degree discharge fitting, if yours is a straight fitting call Jabsco to order a 90. 978-282-5246 is the direct line to Paul Campagna, Jabsco's tech support guy.
You also need a vented loop in the flush water intake line...it does NOT go between the thru-hull and pump...it MUST be installed between the pump and the bowl, which will require replacin the short piece of hose that connects them with two hoses long enough to put it the same height above the toilet as the discharge loop. You'll see illustrations of the correct locations for vented loops in the installation instructions: Jabsco Manual Twist & Lock owners manual Also see the photos I've attached.
Now let's talk about the backup from the holding tank: I'm betting that it's an uphill run from the toilet to the tank and that you're not flushing long enough in the dry mode for the flushes to get there, so they're running back to the bowl. Tank contents may also be spilling into the toilet discharge line when the boat is heeled. The vented loop in the toilet discharge line will keep water from getting TO the bowl from the tank and the thru-hull, but a li'l doodad called a joker valve (one way valve in the toilet discharge fitting...see the exploded drawing in the instruction manual) is needed to keep it OUT of the bowl, and yours is obviously worn out. Joker valves should be replaced in all toilets at least annually.
The vented loop in the toilet discharge line can actually increase the number of flushes your tank can hold while reducing the number of times you have to pump the toilet once you learn how to use the dry mode to do more than just push the last bit of water out of the bowl: Any toilet that's working anywhere close to spec--which includes having a joker valve in good shape--can move bowl contents VERTICALLY up to 4' in the dry mode....more than enough to move 'em over the top of the loop...then gravity can get it the rest of the way to the tank. If your toilet can't push the bowl contents over the loop, replace the joker valve. So--ahead of use, pump a couple of times to wet the bowl if for only urine and TP ...add a couple of beer cupfuls of water from the sink ahead of solid waste. Pump enough times in the DRY mode to push the bowl contents over the top of the loop, then switch to wet for only a few flushes to rinse the line behind the flush.
One more thing: although my book is titled "Get Rid of Boat Odors" (see link in my signature), it's actually a comprehensive "marine toilets and holding tanks 101" manual that will teach you how to prevent 99% of problems instead of having to fix 'em. It's available from the sbo.online store....just click on the link. And I'm always glad to answer any questions it doesn't."
You also need a vented loop in the flush water intake line...it does NOT go between the thru-hull and pump...it MUST be installed between the pump and the bowl, which will require replacin the short piece of hose that connects them with two hoses long enough to put it the same height above the toilet as the discharge loop. You'll see illustrations of the correct locations for vented loops in the installation instructions: Jabsco Manual Twist & Lock owners manual Also see the photos I've attached.
Now let's talk about the backup from the holding tank: I'm betting that it's an uphill run from the toilet to the tank and that you're not flushing long enough in the dry mode for the flushes to get there, so they're running back to the bowl. Tank contents may also be spilling into the toilet discharge line when the boat is heeled. The vented loop in the toilet discharge line will keep water from getting TO the bowl from the tank and the thru-hull, but a li'l doodad called a joker valve (one way valve in the toilet discharge fitting...see the exploded drawing in the instruction manual) is needed to keep it OUT of the bowl, and yours is obviously worn out. Joker valves should be replaced in all toilets at least annually.
The vented loop in the toilet discharge line can actually increase the number of flushes your tank can hold while reducing the number of times you have to pump the toilet once you learn how to use the dry mode to do more than just push the last bit of water out of the bowl: Any toilet that's working anywhere close to spec--which includes having a joker valve in good shape--can move bowl contents VERTICALLY up to 4' in the dry mode....more than enough to move 'em over the top of the loop...then gravity can get it the rest of the way to the tank. If your toilet can't push the bowl contents over the loop, replace the joker valve. So--ahead of use, pump a couple of times to wet the bowl if for only urine and TP ...add a couple of beer cupfuls of water from the sink ahead of solid waste. Pump enough times in the DRY mode to push the bowl contents over the top of the loop, then switch to wet for only a few flushes to rinse the line behind the flush.
One more thing: although my book is titled "Get Rid of Boat Odors" (see link in my signature), it's actually a comprehensive "marine toilets and holding tanks 101" manual that will teach you how to prevent 99% of problems instead of having to fix 'em. It's available from the sbo.online store....just click on the link. And I'm always glad to answer any questions it doesn't."