Update on hose replacement, and follow-up question

[chriscampbell]

I posted last fall about removing old macerator and permeated hoses. I've now replaced most of the hoses with Raritan SaniFlex. The smell is much improved. The only hose I haven't replaced is the short piece from the holding tank to the pump out fitting, only because it's extremely difficult to access.

My follow-up question:
When I replaced the hose from the toilet pump to the holding tank, I used the old hose to measure exactly the length of the replacement hose. Installed, it has a slight dip in the distance between the toilet and tank, and then rises a foot or so to the inlet. This means it would always hold some waste. Is this correct/normal?

 

[Don S/V ILLusion]

Why would you want a hose to store waste? [rhetorical question]

 

[chriscampbell]

Why would you want a hose to store waste? [rhetorical question]

I thought maybe it was intended to have some water in it that was flushed through? I don't know...

So should I read from your comment that hoses should only rise to the tank, and therefore ours is too long (and probably was from the factory)?

 

[Ralph Johnstone]

I've got roughly the same thing. You can't control differences in elevation.

Use supports (foam rubber, wood, hangers, etc,) under the hose to keep it at a constant incline, as much as possible, to ensure the solids have the best chance of getting swept into the tank.

 

[shemandr]

Ideally from the loop to the tank should be downhill so waste doesn't stay in the hose.
In my H356 there was sag in the run by the engine. The was the way I got it. I don't think it's a high priority for builders.
I used to flush with a gallon of freshwater after using the head or at the end of a weekend. That's not the best but it's helpful.
I would get a pump out at every opportunity.

 

[Peggie Hall HeadMistress]

There is a solution to an uphill run from the toilet to the tank that has no sags in it:

I don't know of a single marine toilet, manual or electric, that isn't capable of lifting bowl contents at least 4'...more than enough to put an arch in the toilet discharge line immediately after the toilet (aim the discharge fitting straight up) that's just a couple inches higher than the top of the tank.. That will allow you to flush only long enough to push bowl contents over the top of the arch...gravity will get it the rest of the way. This has the added advantage of using a LOT less flush water...you can even use the "dry" mode if you have a manual toilet or a flush panel that provides 3 options: add water to the bowl ahead of use, which you should always do ahead of solid waste (use a cup from the sink if you don't have this flush panel), dry flush and the same simultaneous water in/bowl contents out that single flush buttons offer. Follow each flush with about a quart of clean water to rinse out the line. Doing this using the "dry" mode will leave less than cupful in the uphill portion of the line to run back down the toilet. Your joker valve needs to be in good condition to keep water in the bowl and to block the runback.

--Peggie

 

[chriscampbell]

There is a solution to an uphill run from the toilet to the tank that has no sags in it:

I don't know of a single marine toilet, manual or electric, that isn't capable of lifting bowl contents at least 4'...more than enough to put an arch in the toilet discharge line immediately after the toilet (aim the discharge fitting straight up) that's just a couple inches higher than the top of the tank.. That will allow you to flush only long enough to push bowl contents over the top of the arch...gravity will get it the rest of the way. This has the added advantage of using a LOT less flush water...you can even use the "dry" mode if you have a manual toilet or a flush panel that provides 3 options: add water to the bowl ahead of use, which you should always do ahead of solid waste (use a cup from the sink if you don't have this flush panel), dry flush and the same simultaneous water in/bowl contents out that single flush buttons offer. Follow each flush with about a quart of clean water to rinse out the line. Doing this using the "dry" mode will leave less than cupful in the uphill portion of the line to run back down the toilet. Your joker valve needs to be in good condition to keep water in the bowl and to block the runback.

--Peggie

Thanks, Peggie. This is a terrible drawing, I know, but this is roughly what ours looks like. The pump hose is mostly flat and runs through a bulkhead to the tank. There is a slight drop in the hose before it goes up to the tank. As someone else mentioned, should I try to put blocking under the hose to eliminate the drop?

 

[Peggie Hall HeadMistress]

Eliminating the sag still leaves you with an uphill run at the end of the toilet discharge line which is likely to leave you with at least some of the flush that doesn't make it into the tank...it depends on how long the toilet discharge line is.

What's the distance from the toilet to tank? What's the make/model of your toilet?

--Peggie

 

[chriscampbell]

What's the distance from the toilet to tank? What's the make/model of your toilet?

--Peggie

I'm not at the boat, but rough guess is 3ish feet from the pump to the tank. It's a Jabsco manual pump. I'm not sure of the model but it's the very common basic model with a wet/dry switch.

 

[chriscampbell]

What's the distance from the toilet to tank? What's the make/model of your toilet?

--Peggie

Also, just found this from the manual. (I removed the macerator connections)

 

[Ralph Johnstone]

Also, just found this from the manual.

I think your "terrible" drawing is much better than the manual's drawing.

In the manual drawing, the macerator pump could never pump out the holding tanks as the pump's suction is near the top of the tank.

 

[Peggie Hall HeadMistress]

That drawing from your manual only makes my case that boat builders are the WORST sanitation plumbers on the planet! 1. The vented loop in the toilet intake is in the right place, but under the vanity is way too low to do any good. It needs to be at least 6-8" above waterline AT MAX HEEL, which on most sailboats puts it 2-3 FEET above the bowl and without any 90s;
2. The intake line makes a 180! 3.The vent line has 3 90s, the elbow fitting on the tank, another one in the vent line and a third one at the vent thru-hull. It shouldn't have any.

--Peggie

 

[chriscampbell]

I think your "terrible" drawing is much better than the manual's drawing.

In the manual drawing, the macerator pump could never pump out the holding tanks as the pump's suction is near the top of the tank.

Ha ha - yes, you're exactly right. The drawing is not representative of how the macerator was actually connected. The pump out fitting on the tank is a T fitting. The top goes to the pump out and the bottom to the macerator. I removed the macerator hoses and capped off the T fitting.

 

[chriscampbell]

That drawing from your manual only makes my case that boat builders are the WORST sanitation plumbers on the planet! 1. The vented loop in the toilet intake is in the right place, but under the vanity is way too low to do any good. It needs to be at least 6-8" above waterline AT MAX HEEL, which on most sailboats puts it 2-3 FEET above the bowl and without any 90s;
2. The intake line makes a 180! 3.The vent line has 3 90s, the elbow fitting on the tank, another one in the vent line and a third one at the vent thru-hull. It shouldn't have any.

--Peggie

I snapped a couple of pics yesterday. Here is the line I am talking about. You can see it runs behind the toilet and then drops down slightly just after it goes through the bulkhead. Poor factory design notwithstanding would you change anything about the house run or leave it alone?

 

[Peggie Hall HeadMistress]

I'd fix it, but that's up to you.

--Peggie

 

[chriscampbell]

I'd fix it, but that's up to you.

--Peggie

So that hose should be shortened so that it only runs flat to uphill to the tank? I guess that would mean that anything that doesn’t make it up the rise will come back into the toilet instead of staying the hose.

 

[Peggie Hall HeadMistress]

I described what I consider to be the ideal fix in post #6.

--Peggie