Waste holding tank pump-out issues

brad614

Petty Officer 2nd Class
Joined
Sep 4, 2010
Messages
158
Yesterday I tried to get my holding tank pumped out but the dockhand at the marina couldn't get it to create any suction. He said there should be a valve to turn it between the marcerator and the pump out outlet, but there doesn't appear to be one. There is the pump on the top of the holding tank and it has two hoses coming off of it, one on either side. One hose goes to the thru-hull fitting for overboard discharge, and the other goes straight up to the pump out fitting on the the deck. What could be wrong? Why couldn't the pump out create suction?
 

Lyle29464

Lieutenant
Joined
Mar 10, 2009
Messages
1,261
Re: Waste holding tank pump-out issues

It cant draw through the pump. your mising something. Maybe a small flip valve?
 

brad614

Petty Officer 2nd Class
Joined
Sep 4, 2010
Messages
158
Re: Waste holding tank pump-out issues

IMAG0226.jpgIMAG0228.jpgI checked again today. I can see the pump mounted to the tank, and the two hoses coming out either end. I traced the lines, and one definitely goes to the thru-hull, and one goes up to the pump-out outlet. I can't find a valve ANYWHERE. Here are a few pictures - what am I missing??
 

sasto

Captain
Joined
Jun 1, 2010
Messages
3,918
Re: Waste holding tank pump-out issues

Hi Brad, That looks to be a vacuum pump that is activated each time you flush your head. Is this the case?
 

brad614

Petty Officer 2nd Class
Joined
Sep 4, 2010
Messages
158
Re: Waste holding tank pump-out issues

Maybe that's what it is - there is definitely a vacuum pump in the system. I will check this next time I am down at the boat. There is a box with a switch that says "Marcerator" on the wall right next to it. I am sooo confused...
 

sasto

Captain
Joined
Jun 1, 2010
Messages
3,918
Re: Waste holding tank pump-out issues

Maybe that's what it is - there is definitely a vacuum pump in the system. I will check this next time I am down at the boat. There is a box with a switch that says "Marcerator" on the wall right next to it. I am sooo confused...


You shouldn't be pumping out thru that pump. Check to see if you have a hose coming from the tank, to a valve that goes to the macerator pump and also the deck waste fitting. Switch the valve and you should be fine.

Good Luck!
 

brad614

Petty Officer 2nd Class
Joined
Sep 4, 2010
Messages
158
Re: Waste holding tank pump-out issues

Ok - the picture is definitely the macerator. I tested it today and watched it pump out. The hose from the other side definitely goes to the waste pump out outlet. There isn't any type of manual valve anywhere!
 

Fireman431

Rear Admiral
Joined
Sep 17, 2007
Messages
4,292
Re: Waste holding tank pump-out issues

There doesn't always have to be a 'Y' valve between the pump out deck fitting and the macerator discharge, as long as the macerator has a shut off valve between it and the discharge port.

In other words, if the macerator discharge port can be closed off with a valve, the system is airtight enough to create a vacuum and pump out the tank. It could be as simple as a deck fitting plumbed directly to the lower portion of the holding tank and pump out happens when the vacuum pump is activated. Your boat should be equipped with a 90? shutoff valve prior to the overboard discharge (lockable) because discharging within 3 miles of a coastline is not allowed.

Is it possible that the deckhand was simply not getting a good seal with the pump out unit (is it threaded vs. rubber cone)? Is he sure that the pump is operating correctly? It's also possible that you may have an inline clog. You don't want a high vacuum directly into the tank. They are vented and you'll never truly get a vacuum. If you did, you would collapse the tank when pumping it out.
 

brad614

Petty Officer 2nd Class
Joined
Sep 4, 2010
Messages
158
Re: Waste holding tank pump-out issues

I am at my wits end on this one. I am about ready to just tell everyone they have to pee overboard! Went to another marina today and had the same issue - couldn't build a vacuum to pump out the holding tank! I realized that the marcerator pump is not actually on top of the holding tank - in fact, I don't even know where the holding tank is!! Even the licensed boat surveyor couldn't find it! I can't find a Y-valve anywhere, and I am tired of spending $20 in gas just to go out far enough to legally pump out my holding tank...
 
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