coopec
N/A
Can anyone tell me what type of pump (e.g. lobe, diaphragms, centrifugal, macerator) preferred to pump out sewage holding tanks? (And maybe why) (I'll be using a macerator to empty the toilet bowl)
Last edited:
Type of pump to empty sewage holding tank?
- Thread starter coopec
- Start date
duncan99210
Well-known member
I use a generic diaphragm manual bilge pump. Why? It was cheap and readily available, does the job getting rid of the jobbies.
ghostlymoron
Well-known member
Diaphragm pump perfectly adequate. A further macerator is not required, after being macerated at the toilet exit, the effluent will be the consistency of thickish oxtail soup and will not re-combine to form lumps.
coopec
N/A
I was hoping the consensus would be diaphragm because they have good self priming capabilities but in any case they won't be damaged if they run dry. I have read that even self priming macerator pumps won't self prime after a couple of years.
Clive
Clive
prv
Well-known member
Another vote for diaphragm pumps, preferably with tricuspid valves rather than flaps. These are what the Lavac toilets use, and while I'm not an unconditional Lavac fan for various reasons, they do have a reputation for being un-blockable. Apparently at boat shows the sales rep used to flush his tie through one 
Pete
Pete
David2452
Active member
Whale gulper is my default for black water tanks, it's a diaphragm pump as recommended above, and a damn good and easily serviced one too.
Chris_Robb
Well-known member
Don't believe the self priming capabilities once there are solids present. I have been struggling for 4 years to get a tank with a Jabsco diaphragm pump to prime it self. It is set horizontally connected to a dip tube, so has to raise the shit about15 inches. I only did it each time I cleaned it - a bit of a pain in the arse..... The manufacturers insist that it installed correctly (they have had photos) but it didn't work consistently - actually only about 10%. So I have now re routed it so that the pump sits vertically and is permanently full of the you know what.
But I would say, if you can mount it this way, you should have much less trouble than a macerator, from hearsay, they apparently don't last that long.
PaulRainbow
Well-known member
Had a macerator on the last boat, worked flawlessly for 4 years and still fine when we sold the boat. Noisy as hell though and as the OP already has a macerator on the bog i'd concur with the diaphram.
Oh, the Lavac might not block easily, but big logs require some leveredge on the handle lol
Oh, the Lavac might not block easily, but big logs require some leveredge on the handle lol
Tranona
Well-known member
As you are starting your installation from scratch, why not design it with a gravity holding tank?
coopec
N/A
Tranona
I have installed my "V" tank below the dining table which is close to the toilet. I find you don't have a lot of choice where to put things and as a result everything is a compromise. I think if you look at the line drawings you will see what I mean.
http://www.finelineboatplans.com/bruce-roberts-sailboat-plans/40-65ft/mauritius-norfolk-43
Clive
Sea Q
New member
Diaphragm pump with a timer, some were easy to activate with a view so you don't accidently pump were people are swimming
With suction off the bottom of holding tank
With suction off the bottom of holding tank
Norman_E
Well-known member
Unless they have improved the design since I bought a Whale Gulper 220 I would not buy one. The problem is an ordinary steel worm gear driving a plastic wheel. The steel gear on mine rusted and ground away the teeth on the wheel. Whale sent me replacement gears but the worm was still ordinary steel, not stainless steel or bronze.
Sinbad1951
Member
Not cheap but excellent is the Sealand T series pump. Built for the American market so used to pumping some serious cr*p.
srm
Well-known member
Henderson/Whale Mk5 or you could get the white 'sanitation' version used on the Lavac toilet. Both will do the job and self prime from a connection on the top of the tank.
Of course these are manual diaphram pumps, that is why they are so are reliable.
Of course these are manual diaphram pumps, that is why they are so are reliable.
Birdseye
Well-known member
I used a diaphragm pump and rigged the system so that it just primed a syphon and then the tank emptied itself
coopec
N/A
Thanks for your opinions. I have a smallish Chinese diaphragm pump which I'll hook up to my holding tank: we'll see how that goes.