Macerator pump line question

[LeslieTroyer]

Peggy I got your book and enjoyed reading it but was left with a question. Right now my system allows me to pump the head to either the tank or overboard (via a y valve and 1.5" thru hull). I plan on moving the y valve and put in a macerator pump for when we are in Canadian Waters. In the book you say to put in a anti siphon valve above water line. And I understand that is to keep seawater from flooding the tank.

Where I'm confused is wouldn't that line always have black water and permeate the hose?? How would you flush this infrequently used line clean??

Also is there a brand of pump that is better than the others??

Thanks

Les

 

[Terry Cox]

Hi Les, Peggie will probably jump in with a warning on this one, but our 1991 boat came standard from the factory as follows:

1. Both electric heads have an anti-siphon valve between the sea water intake and the head macerator/pump.
2. Both heads discharge bowl contents directly to the holding tank.
3. A wye fitting (not a valve) at the holding tank allows me to either empty the tank through a pump out deck fitting or to a macerator pump below tank level that is connected to a through hull valve, not both. The wye fitting is connected to a single tank stand pipe.
4. There is no anti-siphon valve between the through hull valve and the tank.
5. I always close the though hull valve when the macerator pump empties the tank. Leaving it open will allow sea water to slowly bypass the pump impeller and fill the tank. The top of the toilet bowl is above the waterline, so in theory the sea water will fill the tank, creep into the heads to below the bowl rim and stop.
6. In the one case I forgot to close the through hull valve sea water filled the tank and stopped. No sea water came into the bowls.

What I should do, but have not done is when I fill the tank with city water after pumping the tank contents is to clear the tank overboard macerator pump and line with some of that city water. The other matter is the sea water that sits in the head intake hose builds a stink from rotting marine life after a period of time. The first flush has a rotten egg smell, which quickly dissipates.

As far as pumps go, ours are all 1991 Jabsco. Peggie will probably recommend a different brand.

 

[Peggie Hall HeadMistress]

Right now my system allows me to pump the head to either the tank or overboard (via a y valve and 1.5" thru hull). I plan on moving the y valve and put in a macerator pump for when we are in Canadian Waters.

Why? If you're in waters where you can dump a tank, you're in waters where you can flush directly overboard...and one flush at a time is definitely a LOT less damaging to the environment than a tankful! So why would you want to remove your ability to flush directly overboard in favor of sending everything to the tank? If it's because you may not be able to find a pumpout after you've been in waters where you're required to hold, why not just add the ability to dump the tank?

. In the book you say to put in a anti siphon valve above water line. And I understand that is to keep seawater from flooding the tank.

That's correct...and it needs to be at least 6-8" above the waterline at any angle of heel, which puts it above the tank. And btw, there should also be a vented loop (anti-siphon valve) in your toilet discharge line between the y-valve and the thru-hull.

Where I'm confused is wouldn't that line always have black water and permeate the hose??

If the tank discharge fitting is at the bottom of the tank, waste rises already rises in the the hose going to the deck pumpout it to the level in in the tank. The vented loop would be installed AFTER the macerator pump--between it and the thru-hull. Hard to see how water will stand in the line to it.

How would you flush this infrequently used line clean??

You'd pump out the tank and then put enough water into it via the pumpout fitting to rinse it out and turn on the macerator. Let the water run while the macerator pump runs.

As for which brand of pump...I'd go with an electric diaphragm pump instead of a macerator pump Dometic/SeaLand makes the best one. SeaLand T-Series discharge pump

 

[Peggie Hall HeadMistress]

Both electric heads have an anti-siphon valve between the sea water intake and the head macerator/pump

If your toilets have a short hose that connects to the pump to the bowl, the vented loops are in the wrong place (not surprising...boat builders are the worst sanitation system designers on the planet!).. they should have been installed between the pump and the bowl...which of course requires replacing that short piece of hose with two lengths long enough to mount the loop where it belongs--at least 6-8" above waterline at any angle of heel...which on most sailboats puts 2-3 feet above the bowl. However, if your toilets are all-china "thrones" that do not have that connecting hose, the line between the thru-hull and the toilet is the only place TO put a vented loop...in which case there should be a solenoid valve in the loop that's wired to the flush button to open and close the air valve.

What I should do, but have not done is when I fill the tank with city water after pumping the tank contents is to clear the tank overboard macerator pump and line with some of that city water.

Instead of filling the tank, put only a few gallons into it via the deck pumpout fitting, 'cuz that sends the water into the tank at the bottom to stir up any sludge and hold it in suspension so it can be pumped out. Repeat that a couple of times...the third time, leave the water running and turn on the macerator pump. Voila--whole system completely rinsed out.

The other matter is the sea water that sits in the head intake hose builds a stink from rotting marine life after a period of time. The first flush has a rotten egg smell, which quickly dissipates.

Rerouting the toilet intake lines to tee into the head sink drain line will solve that problem. You'll find quite a bit of discussion about how to do this in the archives for this forum...and in detail in my new book.

 

[Stu Jackson]

If your toilets have a short hose that connects to the pump to the bowl, the vented loops are in the wrong place (not surprising...boat builders are the worst sanitation system designers on the planet!).. they should have been installed between the pump and the bowl.

I got your book and enjoyed reading it

Leslie, then you really didn't read the book. Really. You might wanna read it again, since Peggie has been very clear about this in everything she has ever written. She's a GEM and a wonderful resource, but if one doesn't absorb the basics from a first reading, try, try again.

Good luck, and good planning really helps. Why anyone would put all their sh*t into a holding tank FIRST without a means of pumping out or going OB first, makes little sense to me. And West Marine's Advisors are completely wrong about this too, since they neglect completely the option of going overboard OR into the holding tank, which, IMHO, is the best way to do it. Why store stuff only to have to pump it out later?

Between Peggie's book and every single marine head manufacturer's installation instructions, I have a great deal of difficulty understanding why these BASIC questions keep coming up.

Sorry for the rant, but it's all there, right in front of you.

Great book.