Clearing the line from head to holding tank?

Mr Fox

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Aug 31, 2017
204
Marshall 22 Portland, ME
Hi all- looking for some advice on clearing a line from my raritan sea era to my holding tank, which is above the head before I disconnect the hose for any service and for winterizing (I suppose I could just pink the line).

Is there any sort of pump I can install immediately before the holding tank that I could operate when I want the line clear, but that would not interfere with the head pushing waste water (macerated) to the tank?

As it is, the current install has poly-x from the head discharge to the tank (my reason for asking about poly x long term previously) Thus far it is not permeating (and is as far as I know at least 3 years old, was there when I bought the boat).

I don’t want to over complicate things, but in my mind it would be nice to be able to have the line be clear of any liquid when I want it to be. Is there a good trick for this? Disconnect and attach a pump when I am servicing? Trying to avoid any spillage.

Thanks!
 
Dec 2, 1997
8,708
- - LIttle Rock
Are you sure it's the toilet discharge line that's clogged and not a blocked tank vent. A blocked tank vent will cause the system to pressurize, creating back pressure that won't let flushes go down.

All tank vents have two main functions: to provide an escape for air displaced by incoming contents and provide a source of air to replace contents as they're pulled out. When air displaced by incoming waste cannot escape out the vent the tank becomes pressurized, creating increasing back pressure that prevents the toilet from flushing.

Without a source of air to replace contents as they're being sucked out of the tank, the pump will pull a vacuum that'll prevent it from pulling out more than a gallon or two. A particularly strong pumpout can even implode a tank.

The two most common locations for a vent blockage are the vent thru-hull and the other end of the vent line--that end of the hose and the vent fitting on the tank. Start by cleaning out the thru-hull...use a screwdriver blade, ice pick--whatever works. If that doesn't result in a spew out the vent, you'll need to relieve the pressure before removing the vent line from the tank to clean them out...so open the deck pumpout fitting VERY CAREFULLY with a hose at the ready. Be sure you're UPwind of it! Scrape out that end of the vent line and the vent fitting on the tank...replace the vent line.

--Peggie
 

Mr Fox

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Aug 31, 2017
204
Marshall 22 Portland, ME
Thanks as usual for the helpful info Peggie- I realize my saying I need to clear the line was not misleading. I should have said empty.

I do not have a clog, the system works great. I was simply wondering if there is a way to fully empty/drain the discharge from the head line, since the run from the discharge to holding tank is uphill.

I want to do this for when I have to replace the joker valve or do any other maintenance on the head. I can figure out something when hauled and I have a still, not rocking around boat, lots of time and buckets and cleaning supplies, but if I have a failure while out, and I need to replace a part, I’d like to be able to empty this line as I would hate to disconnect it when it is full of and then dump that water into my cabin or anywhere onboard for that matter!!!

So I was hoping maybe there is some kind of pump I can put in at the tank end of the head discharge line that I would only use to empty the discharge line fully for the times I need to disconnect it, but that would not interfere with the flow when that “emptying” pump is off. Basically one that allows unrestricted flow past the pump when it is off. Does that make sense?

That make be a Rube Goldberg solution and perhaps there is a far simpler method that people use?

Any ideas?
 
Last edited:

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I understand what you are asking, and it got me wondering about my installation, too. My toilet pumps uphill, too. I carry a spare pump assembly, but if I had to replace it, assuming the old one is not working, I won't have a way to clear the waste before disconnecting it. I could have bowl contents and hose contents all over the head floor.

I don't think an in-line pump is available that will do what you seek. Maybe a big, plastic ball valve on the discharge line close to the bowl would lessen the mess.

Meanwhile, when you flush, make sure you flush enough so that only mostly clean seawater sits in the hose.

Interested to see if someone has a clever solution.
 
Dec 2, 1997
8,708
- - LIttle Rock
Any manual toilet that's working anywhere near spec can move bow contents up to 4' in the dry mode...so learn to use the dry mode to do more than just push the last of the water out of the bowl. First push the flush over the top of the loop...follow it with enough clean water to rinse the hose behind the flush--also in the dry mode. At most there'll only be about 1/2 cup of water to run back down to the toilet. There are other advantages to it: you only have to flush long enough to push the flush over the top of the loop...gravity will get it the rest of the way to the tank. This reduction in flush water can increase the number of flushes your tank can hold by 50% or even more...which, depending on the cost of pumpouts in your neck of the wood, also saves money. This also applies if you have an electric toilet that offers a "dry flush" option.

Keeping a manual toilet working to spec does require replacing the joker valve annually--spring recommissioning is the time to do that...and keeping the toilet well lubricated.

--Peggie
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
depending on the cost of pumpouts in your neck of the wood
Are there really places where you have to pay for a pumpout? I haven't encountered any. Around here they all take the federal funds for facilities, etc., which requires that they pump for free.
 
Jul 29, 2004
406
Hunter 340 Lake Lanier, GA
Are there really places where you have to pay for a pumpout? I haven't encountered any. Around here they all take the federal funds for facilities, etc., which requires that they pump for free.
Yes, there are. For instance, here on Lake Lanier I pay $10 at my marina, and have to go to the fuel dock to get it done. I would have to pay more at other marinas, or much more if I had a large cruiser or houseboat. Or I could pay a floating pumpout service to come to my dock either on call or on a subscription basis, I believe that's $30/visit. Georgia even has a law saying ANY connection between the toilet or holding tank and the water is illegal on this lake and about 4 others that serve as municipal water supplies, but they don't bother to subsidize us rich boaters.

So consider yourself lucky.
 
Dec 2, 1997
8,708
- - LIttle Rock
How can you follow it with water in dry mode? This doesn't make a lot of sense to me.
Surely you're smart enough to figure out that to flush water out of the bowl , you first have to bring water INTO the bowl... <sigh>... Most people would just switch to the wet mode for a few pump strokes, but a couple of cupfuls from the sink works too.

--Peggie
 

Mr Fox

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Aug 31, 2017
204
Marshall 22 Portland, ME
So I can run my electric head (sea era) with the intake closed; the macerator pump happily empties the bowl. I can do a freshwater flush by adding water to the bowl and running it dry as well. My intake pump is a diaphragm type so this is fine.

This would still leave water (at this point clean if I flush enough) in the head discharge to holding tank line- right? The line is about 18’ long and has a rise of 2’ 6” over that run.

What I am interested in is a way to easily (and neatly) empty all liquid from that line. Can I install a diaphragm pump at the end of this discharge line that would run when the head runs, and could also be operated individually to empty the line?

Then I’d have three pumps to possibly break, oh boy! Perhaps I am making this too complicated.
 
Dec 2, 1997
8,708
- - LIttle Rock
This would still leave water (at this point clean if I flush enough) in the head discharge to holding tank line- right? The line is about 18’ long and has a rise of 2’ 6” over that run.
Oh dear...I misunderstood how your tank-toilet is plumbed...I thought you were asking how to eliminate water in a discharge line that goes up and over a loop then down to the tank...which, with an 18' run from the toilet to the tank is the only good way to plumb it. 'Cuz although the high end all china "thrones" have pumps that can push it that far, 6' is about as far as most manual and electric toilets can move bowl contents in the amount of time anyone wants to spend flushing. Getting much further uses a LOT of flush water. A loop (doesn't have to be a vented loop, just a loop if you're only flushing into a tank) immediately after the toilet--aim the discharge fitting straight up) that's just an inch or two higher the top of the tank provides the gravity needed to get the flush to the tank with minimal flush water. I think my first reply (post #5) will make a lot more sense to you now.
So sorry for the confusion!
--Peggie
 
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Mr Fox

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Aug 31, 2017
204
Marshall 22 Portland, ME
Ah, I was wrong also, the run is 10’ but the loop still seems smart.
 

ToddS

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Sep 11, 2017
248
Beneteau 373 Cape Cod
So I've been reading/following-along, and I totally "get" Mr. Fox's concern, but I don't really understand Peggy's response. I'm NOT doubting Peggy... I'm just not understanding. If the hose leaving my manual head goes UP to the tank (like Mr Fox's only a shorter run), how can ANY amount of flushing (freshwater or intake water) fix the problem that's going to happen when I (or Mr Fox) disconnects the hose from the head's discharge fitting? I feel like at best, I could get the water to be "clean-ish" by flushing... but never dry in there. Even pumping on the "dry" setting isn't going to push all that liquid uphill to the tank (in my mind at least)... I always just assumed any air that gets pumped through when pumping "dry" just bubbles up through the liquid in the hose into the tank. My rough estimate is that his 10' hose probably has a gallon or so of content, not 1/2 cup. I must be missing something because I can't picture a bubble of air leaving the head under pressure from the manual pump and "pushing" the contents of a 1.5" hose uphill for a distance of 10', rather than bubbling through it, sending air to the top and anything more dense to the bottom (and the bottom is the hose just downstream of the head right? The physics in my head is telling me that In TINY hoses (think drinking straws) the surface tension of the water against air bubbles is enough that I can blow upwards through a water-filled straw, sending the water upwards... but a large diameter cylinder (think drinking glass) just lets air at the bottom pass through the liquids without lifting the liquid. What moves that "last gallon" of contents. up the hill to the tank?
 
Dec 2, 1997
8,708
- - LIttle Rock
If the hose leaving my manual head goes UP to the tank (like Mr Fox's only a shorter run), how can ANY amount of flushing (freshwater or intake water) fix the problem that's going to happen when I (or Mr Fox) disconnects the hose from the head's discharge fitting?
Whatever water is left the toilet discharge line WILL run back down to the toilet...which is why you'd put a plastic garbage bag under the connection before you remove it to catch the spill--which hopefully will be clean water. It'll be more than half a cup, but the flush water doesn't break and start to bubble till it's gone 5-6' from any toilet that's working anywhere near factory spec...but that requires replacing the joker valve at least every 2 years, preferably annually, which requires removing the discharge fitting from the pump so it's unlikely you've ever replaced it. Find my article "Joker Valve 101" in the archives (it's also in my book) to learn what the joker valve's most important function is...and it's NOT just to block backflow as most people think. The spill still shouldn't be anywhere near a gallon, more like a couple of quarts, but a garbage bag can collect that much.
---Peggie
 

ToddS

.
Sep 11, 2017
248
Beneteau 373 Cape Cod
Thanks Peggie.
I've replaced it several times on the other boat I used to own (with a different head configuration), but I'm less than 2 years into owning my newer boat, and plan to change the joker valve when this season ends (soon) between season 2 and 3. So I haven't ever changed it in THIS boat. My previous boat had a run to the tank that was pretty level (actually slightly downhill) so the joker valve had an easier job... as did the guy (me) who had to replace it ;) Jabscos on both boats, both "came with the boat"... so far the new one has behaved well except a small amount of backflow which I anticipate will be made better with the new joker. With my old boat, I was able to take the line off the back of the toilet with the joker still on it, preventing nearly all spillage (still want a bag just in case of course) and enough of a run to allow me to raise the hose up high after detaching, making gravity work in my favor. The new boat only has a very short length of hose exposed before passing through a bulkhead and going up several feet towards the tank, so I won't be able to quickly/easily hold the hose up high to drain it in the right direction. Not too worried though... like you said... a garbage bag is more than capable of catching any spill there. Again, thanks!
 

Mr Fox

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Aug 31, 2017
204
Marshall 22 Portland, ME
Peggie I am wondering can the pump in dry mode push air behind the column of water to keep moving the water itself or will it just bubble air through the column of water?

My system (raritan sea era) is well maintained and it seems I get a very small amount of water returning to the bowl when the boat sits for a week. Like an inch of clear water but this is only in the small area at the very bottom of the bowl where the outlet is (maybe a 4” diameter I guess).

I’m asking so that I can understand better how it works, thanks so much for your insight.
 
Dec 2, 1997
8,708
- - LIttle Rock
Peggie I am wondering can the pump in dry mode push air behind the column of water to keep moving the water itself or will it just bubble air through the column of water?
Any toilet that's working anywhere near factory spec can push bowl contents up to 6' in the dry mode before breaking apart into bubbles. "Factory spec" requires a joker valve that's minimally worn.

--Peggie
 
Oct 11, 2019
27
Catalina 30TRBS New Bern
fwiw, I recent did this with a jabsco (joker valve and flapper)...I pumped a little bit vinegar before I worked on it to make me feel better. a few dry pumps after the liquid was more than enough to make this a dry change with relatively few drops of grey water. hope this helps.