Jabco manual

[johnalison]

Just makes me glad that our holding tank has a pump to pump it out and a changeover valve to pump straight to ocean when it’s not in use.

Nonsense. Gravity has been around for a long time and has never been known to fail. I’m with you on the changeover valve though.

 

[Fr J Hackett]

You would end up with a similar problem surely if it’s blocked? Our own boat is gravity fed and has never blocked unless somebidy has put paper down it which has happened twice in 10 years. But I’ve a lot of experience with other boats where people do use holding tanks and paper.

I have direct experience of both types one like JMs with a Henderson pump no problems with toilet paper and the other with a gravity discharge as well as deck pump out, I won't say it was totally unproblematic with toilet paper use when the discharge would occasionally become sluggish until the paper or whatever it was worked it's way through. I suspect it was someone using copious quantities of paper and screwing it up so that it took time or didn't disintegrate in the holding tank. On one occasion I had to get the tank pumped out from the deck. If you want a totally unproblematic experience that caters for toilet paper a macerator is the answer.

 

[john_morris_uk]

Nonsense. Gravity has been around for a long time and has never been known to fail. I’m with you on the changeover valve though.

Not nonsense. I respectfully suggest that a minor hold up that the force of gravity doesn’t deal with might be cleared very easily with the suction of the hand pump that empties our holding tank. We’ve got a shore pump out option as well.

And we have no problem with moderate amounts of toilet paper. In fact we’ve never had a blockage of the tank with our use.

I inherited a blockage that I ignored for 15 years and just didn’t use the storage tank but that’s another story.

 

[Tranona]

I have direct experience of both types one like JMs with a Henderson pump no problems with toilet paper and the other with a gravity discharge as well as deck pump out, I won't say it was totally unproblematic with toilet paper use when the discharge would occasionally become sluggish until the paper or whatever it was worked it's way through. I suspect it was someone using copious quantities of paper and screwing it up so that it took time or didn't disintegrate in the holding tank. On one occasion I had to get the tank pumped out from the deck. If you want a totally unproblematic experience that caters for toilet paper a macerator is the answer.

I had the first 2 tanks I installed custom made with the pump out immediately above the the outlet to the seacock specifically so that it could be rodded without removing the inspection hatch.

 

[RupertW]

I have direct experience of both types one like JMs with a Henderson pump no problems with toilet paper and the other with a gravity discharge as well as deck pump out, I won't say it was totally unproblematic with toilet paper use when the discharge would occasionally become sluggish until the paper or whatever it was worked it's way through. I suspect it was someone using copious quantities of paper and screwing it up so that it took time or didn't disintegrate in the holding tank. On one occasion I had to get the tank pumped out from the deck. If you want a totally unproblematic experience that caters for toilet paper a macerator is the answer.

But it’s so simple to use the Greek way then why bother.

 

[johnalison]

Not nonsense. I respectfully suggest that a minor hold up that the force of gravity doesn’t deal with might be cleared very easily with the suction of the hand pump that empties our holding tank. We’ve got a shore pump out option as well.

And we have no problem with moderate amounts of toilet paper. In fact we’ve never had a blockage of the tank with our use.

I inherited a blockage that I ignored for 15 years and just didn’t use the storage tank but that’s another story.

The only blockage I have encountered was on a friend's 2nd hand Island Packet, when a kitchen towel from the previous owners created havoc on a cruise we shared, and some hilarity among the rest of us. I see no reason why my gravitational tank shouldn't give a further 23 years of trouble-free service, loo paper and all. I remain suspicious of systems where all effluent is taken through the holding tank, such as my friend's, wherein a problem with the tank or pump can lead to unhappiness.

 

[john_morris_uk]

The only blockage I have encountered was on a friend's 2nd hand Island Packet, when a kitchen towel from the previous owners created havoc on a cruise we shared, and some hilarity among the rest of us. I see no reason why my gravitational tank shouldn't give a further 23 years of trouble-free service, loo paper and all. I remain suspicious of systems where all effluent is taken through the holding tank, such as my friend's, wherein a problem with the tank or pump can lead to unhappiness.

I completely agree with your sentiments re all effluent going through the holding tank. I appreciate it’s the way some boats are plumbed but it’s not my preferred choice.

A nice big valve to choose ‘To Tank’ or ‘To Ocean’ works for me.



I’m still convinced that having a pump to physically empty the tank is superior to a valve and relying on gravity.

 

[RupertW]

I completely agree with your sentiments re all effluent going through the holding tank. I appreciate it’s the way some boats are plumbed but it’s not my preferred choice.

A nice big valve to choose ‘To Tank’ or ‘To Ocean’ works for me.

View attachment 156199

I’m still convinced that having a pump to physically empty the tank is superior to a valve and relying on gravity.

But why when gravity is such a simple solution compared to a pump?

 

[Fr J Hackett]

But why when gravity is such a simple solution compared to a pump?

I think the reasons have been covered already in the thread.

 

[RupertW]

I think the reasons have been covered already in the thread.

Not really apart from the concern that all effluent goes through a holding tank in a typical gravity solution. For a solution to better it has to simpler (gravity), less effort (gravity), less prone to blockages (gravity if no paper) or simpler to fix ( could be either )

 

[john_morris_uk]

Not really apart from the concern that all effluent goes through a holding tank in a typical gravity solution. For a solution to better it has to simpler (gravity), less effort (gravity), less prone to blockages (gravity if no paper) or simpler to fix ( could be either )

Gravity may be simple, but it’s not as powerful as a pump.

 

[Fr J Hackett]

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