Joker Valve not Working

wonkywinch

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Are you sure the pipe from the pan outlet goes to the bottom of the black water tank? That doesn't make sense, you'd be pushing contents upwards against the weight of stuff already in the tank, solids settle at the bottom that could block that narrow pipe etc.

In your pic, is the syphon mounted a little low? I thought it should be above the top level of the tank.
 

Irish Rover

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Are you sure the pipe from the pan outlet goes to the bottom of the black water tank? That doesn't make sense, you'd be pushing contents upwards against the weight of stuff already in the tank, solids settle at the bottom that could block that narrow pipe etc.

In your pic, is the syphon mounted a little low? I thought it should be above the top level of the tank.
There are only 2 hoses at the top of the tank - see photo below - one is the deck pump out and the second is the vent. I can't get a photo of the hose going into the bottom of the tank because it goes through the shelf the tank sits on. As I said earlier I believe the toilet discharge hose is connected to an internal pipe inside the tank which takes the waste to the top for discharge into the tank. There's a name for this pipe but it escapes me. The internal pipe keeps the pressure of the contents off the hose.
My understanding is the anti syphon has nothing got to do with the tank. It's on the sea water intake side and needs to be above the level of the toilet, which it is.20241018_144144.jpg
 

johnalison

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Sorry, but I really don't understand this. I've never encountered a system with valves on the discharge hose between the toilet and the tank.
You may not have, but this is what we have. Our gravity-emptying tank sits on the other side of a bulkhead from the heads and there is a ‘seacock’ diverter valve which leaves the head either open to the tank or the sea outlet. After flushing into the holding tank it makes sense to close the valve. If necessary, such as being in inland waters, the outer seacock can also be closed.
 

Irish Rover

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You may not have, but this is what we have. Our gravity-emptying tank sits on the other side of a bulkhead from the heads and there is a ‘seacock’ diverter valve which leaves the head either open to the tank or the sea outlet. After flushing into the holding tank it makes sense to close the valve. If necessary, such as being in inland waters, the outer seacock can also be closed.
Ok I understand now. I've had gravity discharge tanks in 3 boats but never had a diverter valve. While it adds another potential blockage risk, I can see how it could be useful for distinguishing between a number 1 and number 2 discharge.
 

Irish Rover

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Are you sure the pipe from the pan outlet goes to the bottom of the black water tank? That doesn't make sense, you'd be pushing contents upwards against the weight of stuff already in the tank, solids settle at the bottom that could block that narrow pipe etc.
Looks like I was wrong in what I said before particularly #44 - mea culpa. Looking for something else in the Owners Manual today I came across a photo I probably should have looked at before. It actually shows the inlet hose from the toilet discharge coming up along a blind side of the tank and integrated into to top side. It doesn't have any bearing on my problem but I just want to correct what I said before
20241108_111008.jpg
 
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