Macerator not pumping in GS 232

[PaulinSeattle]

Does anyone have experience with the macerator not pumping the contents out of the tank in a Gulfstream 232?
I have an '04 GS 232, it had the original Sealand 960 series Sanipot, with the holding tank plumbed to a Y-valve for overboard discharge through the macerator pump or to a deck pumpout. When I have Y-valve to overboard discharge and run the macerator pump, i hear it running but it's not pumping anything. I went and replaced the macerator pump thinking the impeller had gone bad, and I replaced the original Sealand 960 sani-pot with a new Dometic 960 sani-pot (same model, just brand new). I filled the holding tank with water and hooked everything up, but still not pumping material out of the tank. With boat on trailer, I can feel air blowing out of the through-hull discharge.
I think disconnected the pickup 1 1/2" line at the sani-pot, and stuck a hose in there and sprayed it while running the macerator and the pumped picked up a prime and sucked out all the water i was spraying in with the hose. I hooked it back up to the sani-pot tank, and it wouldn't pump out. Anyone have any ideas for me to try?

 

[Hookup1]

Put a picture or two up of your tank and macerator. What is the manufacturer and model of the macerator.

Older GW used a in-tank Groco macerator. I switched to a Jabsco. It has the ability to "lift" material from the tank into the pump. This is a great pump but you can burn the impeller up if it doesn't prime quickly.


Beginning of season I have had problems with the pump impeller going dry. I disconnect discharge hose, install a 3' piece of vinyl hose, fill the hose with water and cycle the pump into a bucket. Then I see if the pump will empty the tank into the bucket. It's really important that all the hose connections are tightly sealed up - if there is an air leak the pump won't "lift". If this doesn't work check the impeller. I had one that looked good but took a set and wouldn't pump.

 

[seasick]

If the pump dose not support self priming, it has to be 'wet' (in standing water) to pump. That means that both the Y valve and the plumbing/pump have to have fluid in them. You issue could be as simple as the case where you installed the new pump and repositioned one of the hoses to a higher spot or inadvertently added a upward loop to a hose run ( between the tank and the Y valve.

Also, if the new pump is not rated for 'run dry' use, you may have fried the impeller