Failing macerator pumps

[meshugah]

Hi, I have had a Catalina 42Mk2 for 20 years and the worst job on the yacht is changing the macerator pump, which occurs every 2 years of so. Its such a messy process and smells out the boat. Sometimes I can't avoid getting excrement into the bilge and that becomes an awful clean-up job. I have been using Johnson TA3P10-19 macerator pumps for years but am now thinking that there must be a better solution. The other pumps on the yacht (fresh water, shower sump etc), rarely if ever, need replacing, but the old macerator can be counted on to fail just when you need it most. I'm not sure why the macerators fail so reliably, perhaps we use too much paper and they get blocked and then run dry killing the pump. Does anyone have any suggestions for a way to improve the reliability of black water tank pump-out? Perhaps I should use a more industrial grade pump. Suggestions very welcome.

[peghall]

It wouldn't happen if the tank and the macerator pump are rinsed out with clean water at least after every 2-3 uses. Waste is sticky, causing the impeller to get stuck at least temporarily every time the macerator is started which results in over heating the motor and/or cracked impeller vanes, shortening the life of pump.



--Peggie

[sailorboy1]

Originally Posted by peghall

It wouldn't happen if the tank and the macerator pump are rinsed out with clean water at least after every 2-3 uses.

--Peggie

It still happens based on my my 7 years on living on a boat. I try to flush mine out just so the poop isn't sitting in it, but it doesn't seem to impact the pump life much.

I have used the Jabsco and Seaflo macerators. They last about the same about amount of time. But I like the Seaflo better as the end screw is easier to get at and it costs less

[jtsailjt]

After several messy and disgusting experiences replacing various brand macerators I replaced mine with a Whale Gulper 5 years ago and haven’t had a problem since. Another advantage is that, unlike macerators, it’s ok to let it run dry which seemed to happen fairly often as I’d get distracted while pumping out the holding tank. I also use these same Gulper pumps for shower sumps and one of my bilge pumps so only one rebuild kit onboard for all 4 pumps. Without getting too descriptive, the output isnt as finely ground as with a macerator but it’s still almost all liquid with very few small chunks of solids.

[peghall]

Switching from a macerator pump to a diaphragm pump may be the only solution. The Dometic/SeaLand T-Series "SaniPump" is the best one. Cost is about double that of a macerator pump but should end up being less in the long run because it needs very little maintenance (rarely more than a periodic rinse and 2 duckbill valves every couple of years ) and can last for literally decades...the one on one of my own boats was 11 yrs old when I sold the boat and still going strong.

SeaLand T-Series Pump at Defender


--Peggie

[Dockhead]

Whale Gulper is a great pump.

All of my gray water goes through a small tank to be pumped overboard with one of these. I'm still on the original Whale Gulper, which is now 22 years old, and has handled God knows how many millions of liters of icky gray water (showers, washing machine, sinks). I've replaced the diaphragm several times, however. These are very robust devices.

HOWEVER, it doesn't macerate, so I don't think I would use one of those for black water unless all of your toilets are macerating (mine are). With all macerating toilets, I think it would be great.

For black water, I'm still on the original Jabsco macerator pump which is still going strong. I've replaced the impeller a few times, and once did the Jabsco upgrade of the corrosion-prone bolts. I don't quite fathom how it's possible to wear them out every two years.

[peghall]

Solids are are 75% water, have already been broken up, if not already macerated, by the toilet pump, and therefore dissolve very quickly in the tank, as does quick-dissolve TP. Plus, diaphragm pumps, both manual and electric, "musherate" (I wish I'd been the one who thought up that word) what goes through them, making maceration unnecessary.


--Peggie

[Bowdrie]

Originally Posted by peghall

Switching from a macerator pump to a diaphragm pump may be the only solution. The Dometic/SeaLand T-Series "SaniPump" is the best one. --Peggie

Agree.
Expensive? yes, but you only cry once.

[Dockhead]

Originally Posted by peghall

Solids are are 75% water, have already been broken up, if not already macerated, by the toilet pump, and therefore dissolve very quickly in the tank, as does quick-dissolve TP. Plus, diaphragm pumps, both manual and electric, "musherate" (I wish I'd been the one who thought up that word) what goes through them, making maceration unnecessary.

--Peggie

If you say so -- I've certainly not done any actual research.


I do, however, notice a dramatic difference in the frequency of clogs in black water lines between boats with electric macerating toilets and those with manual ones.


So I, personally, would not run one of these systems without maceration at least somewhere in the system.


But then again I would never go back to a non-macerating toilet, so it's a non-issue for me. YMMV.

[meshugah]

Thank you all very much for your valued suggestions. My current thinking is to replace the macerator pump with one of the suggested alternatives. Many thanks once again for the valued input.

[nightowle]

Meshugah; I like your handle!

[meshugah]

Yes, the name Meshugah is the name of my yacht. It accurately describes the person I am. One needs to be quite meshugah to spend so much time and money messing about with a yacht. But, I can't help myself, because I love everything about it so much! (Apart from changing macerators pumps!).

[rdempsey]

I used to work at a Marine wholesaler. We sold sssoooo many macerator pumps.
Try to avoid them if you can. Diaphram pumps are better.

[s/v Jedi]

I recommend a macerating toilet with fresh water flush and this pump: https://defender.com/en_us/whale-gulper-toilet-pump

(There are many variants of this pump… the link points to the correct one)

[meshugah]

Thank you again for the tips to avoid macerator pumps and to switch to a diaphram pump instead. Many years ago I actually switched from saltwater flushing to freshwater flushing as the saltwater reacts with the effluent and caused pellets to deposit on the floor of my blackwater tank, obstructing the output port, making it impossible to pump out the tank. Ever since I switched to freshwater flushing that problem has disappeared. The downside is that it increases the demands on the supply of fresh water. I solved that problem by installing an Australian made Rainman water maker, which has not let me down since I bought it some years ago. I also made a couple of changes to the black water tank. Firstly, I installed a Vetus Inspection port into the top of the tank so that I could actually see the level of waste inside (if required) and to provide access to the output port in the event that it got blocked. (I would be able to poke something down into the tank if required). I also relocated the output port to the lowest part of the tank, which has enabled me to pump out more of the waste than was possible previously. In addition I inserted a valve at the output so that if I needed to do some emergency plumbing, I could restrict the volume of waste coming into the output hose. These changes have made the system much more user friendly. Replacing the macerator pump with a diaphram pump will also improve the system greatly.