Macerator Pump or Diaphragm pump for overboard discharge

[felizcortez]

I currently have a Jabsco macerator pump for the overboard discharge on my boat. It lasted about 6 months of heavy use and I had to pull it apart this week because it was running sluggishly. I think I need a new impeller, but it isn't running at 100%. I am debating on whether it would be a better idea instead of replacing the impeller or macerator with the same as I have now if I should get a Diaphragm pump instead. I would need to a small rerouting to to plumb in a Diaphragm pump.

My current system consists of a Jabsco manual head that goes to a Y valve that goes either directly overboard or goes to the holding tank. I then have the macerating pump to pump the tank overboard.

A few questions.
1. Is a Diaphragm pump a better fit than the macerator in my scenario?
2. Since the toilet is a manual head would it matter if there was no macerator.
3. If I got a Diaphragm pump which one would you recommend?

I also have two lines coming off the tank one is a vent line which I plan to replace with a. 1 inch hose and corresponding through hull. There is a second hose which goes to a fitting on deck which looks like a garden hose inlet fitting. I think the fitting is shot, but I don't believe this one is necessary and I might run it as a second vent line to get more air circulation. I am getting some smell coming out of the vent line right now.

[Tayana42]

I can’t say what is best for your situation but I use a manual diaphragm pump to empty my holding tank. It works fine and has never clogged. I have no macerator but my head is a VacuFlush. My pump is a Whale Gusher Titan with a nitrile head. By the way it takes about 50 strokes to empty my 40 gallon holding tank.

[HopCar]

Diaphragm pumps tend to need less maintenance than macerator pumps.
Your current pump has a 1-1/2 intake and probably a 1” discharge hose going to a 1” seacock.

To switch to a diaphragm pump you’ll probably have to change the discharge hose and seacock / thru-hull to 1-1/2”. This could get pretty expensive. You don’t want to make the change until your next haul out.

The Sealand T series pump is very good.

Tayana makes a good suggestion. Can’t get much more reliable than a manual diaphragm pump, and it’s not very expensive. The Whale Titan is a good value. Carry a spare diaphragm and valves and you’re all set.

[RaymondR]

Originally Posted by HopCar

Diaphragm pumps tend to need less maintenance than macerator pumps.
Your current pump has a 1-1/2 intake and probably a 1” discharge hose going to a 1” seacock.

To switch to a diaphragm pump you’ll probably have to change the discharge hose and seacock / thru-hull to 1-1/2”. This could get pretty expensive. You don’t want to make the change until your next haul out.

The Sealand T series pump is very good.

Tayana makes a good suggestion. Can’t get much more reliable than a manual diaphragm pump, and it’s not very expensive. The Whale Titan is a good value. Carry a spare diaphragm and valves and you’re all set.

Carry two complete pumps so that you can soak the removed one in a strong cleaning fluid for a week or so before you overhaul it.

[CassidyNZ]

Originally Posted by felizcortez

There is a second hose which goes to a fitting on deck which looks like a garden hose inlet fitting. I think the fitting is shot, but I don't believe this one is necessary and I might run it as a second vent line to get more air circulation. I am getting some smell coming out of the vent line right now.

The second line to the deck is probably intended as a suction connection for marina pump out facilities. But if it is intended for that it shouldn’t have a “garden hose fitting” on it. Also, if you intend to use marina pump-outs in the future, a good quality breather is essential. Many marina pump-outs have enough suction to implode the holding tank if it doesn’t breathe well.

A good breather will also reduce smell (aerobic as opposed to anaerobic). I have a small carbon filter on mine.

[felizcortez]

Originally Posted by CassidyNZ

The second line to the deck is probably intended as a suction connection for marina pump out facilities. But if it is intended for that it shouldn’t have a “garden hose fitting” on it. Also, if you intend to use marina pump-outs in the future, a good quality breather is essential. Many marina pump-outs have enough suction to implode the holding tank if it doesn’t breathe well.

A good breather will also reduce smell (aerobic as opposed to anaerobic). I have a small carbon filter on mine.

There is a separate deck fitting for the pump out then a second fitting that has a garden hose connection, then a 3rd which is the vent line.

The macerator pump has a 1 inch output which has a 1 inch to 1.5 inch converter which then goes to a 1.5 inch hose and through hull.

For the manual pump, I am putting it inside a locker, so I may not have room for the pump handle.

[GILow]

Double check the regulations where you sail. The macerator may be required to reduce the discharge particle size.

[HopCar]

Are you sure the hose that goes to the garden hose fitting goes to your black water tank? It sounds like an inlet for fresh water that is meant to supply water to your fresh water system while at a dock. It would run to a Tee in your water system.

[felizcortez]

Originally Posted by HopCar

Are you sure the hose that goes to the garden hose fitting goes to your black water tank? It sounds like an inlet for fresh water that is meant to supply water to your fresh water system while at a dock. It would run to a Tee in your water system.

I'm positive it goes to the waste tank. I've traced the lines. The water fill fittings are also on the complete opposite side of the boat.

With regards to particle size, if you flush directly overboard it never goes through a macerator. I'm currently cruising Mexico.

[Smokeys Kitchen]

We too had a macerator pump when we first got the boat. Rebuilt the entire head/waste system and went with a Viking Power 32 waste pump (diaphragm) by Jonhson. No strainer to clean, self priming, and it can run dry.

Seems to be very robust; 3 years of living aboard now and no issues. FWIW the pump comes with a rotary handle that can be used to manually cycle the pump if the electricity goes out. We do have a manual Groco head which pretty much macerates the effluent as it is pumped into the holding tank

https://www.spxflow.com/en/johnson-p...wer-32-vacuum/

[Mojadito]

I agree with Hopcar, the Sealand T series is definitely the way to go, been using mine for 10 years, never had clogged. I always flush with plenty of seawater after the discharge.

[briblack]

we changed to a diaphragm pump (whale). no further problems.

[Marathon1150]

We have a manual (Whale) pump located in a locker immediately behind the head. Discharge from the head can be sent directly overboard or into a holding tank, using a Y-Valve. We empty the holding tank with the manual pump and it has worked flawlessly for more than 15 years. We have changed the hoses a couple of times but otherwise, all has worked well.

BTW, the handle can be removed from the pump to reduce its overall size except when using it.

[CassidyNZ]

Originally Posted by felizcortez

There is a separate deck fitting for the pump out then a second fitting that has a garden hose connection, then a 3rd which is the vent line.

Perhaps the fitting with hose connection is intended to introduce fresh water to the holding tank for flushing/washing-out operations? It would worry me ever so slightly though, that I may be using a hose to take on drinking water that has just been connected to someone else’s holding tank.

[sailcrazy]

We have a similar system, except ours is an electric toilet with B/I macerator; discharge goes to a "Y" valve, and then to a holding tank or overboard. But the macerator pump we had installed would not empty the holding tank, even though the vertical lift was less than 2'. We tried everything, including rebuilding the pump, and then changing pump manufacturers.....it still did not work. I bought and installed an electric waffle pump, and it works perfectly! Don't understand all I know about the system, but I'd strongly recommend a waffle pump-manual or electric.