... I have the Jabsco Self Priming (not really) Macerator Pump #18590 (impeller pump) connected from my Holding Tank to the Overboard Discharge line. I've had two of these pumps in 8 years, both have failed, both leaked a little at the housing after some time (no freezing) and neither one primed very well. I never use the Holding Tank (we are exclusively offshore in the Bahamas), but when I do want to use the pump, I have to manually prime it by taking off a hose and filling it with water that reaches the pump. Then it primes and works fine for a while, but after a couple months, I again have to manually re-prime it. I guess the impeller could be worn, but I don't think so, as this has happened twice and I understand from others Jabsco's Self Priming Macerator isn't really self-priming.

I am thinking the #50890, a diaphragm pump, will be a better pump ... and am wondering if others use it to evacuate Holding Tanks without any problems ?

Link > www.defender.com/product.jsp?path=-1|51|299222|84462|315208&id=1029486

Thanks, cheers, John