HELP - Holding Tank won't Pumpout - Completely

[B00ST]

Hi all -

Just joined - found a lot of good info already on your site... Here's my delima. I have a holding tank that will pump out for a bit, then suddenly stops. There is Waste still in the tank. I've got it down to a 1/2 tank now by building up pressure in the pumpout then quickly turning the valve...but it has taken forever. I thought that there might be something in my holding tank that is causing a blockage, ie it pumps out for a bit then this foreign obstacle gets lodged. I spent most of the day yesterday trying to run a snake down the thing...but it didn't bring anything back up. I've also ran a hose from the pump out to the tank and I can see water coming into it with a flashlight. I'm completely at a loss....getting ready to turn it over to the pro's .... but I am sure that is going to cost an arm and a leg...as well as my first born.

Let me know if you have any advice.
Thanks in Advance - Rob

[Alondra]

Ok... check this. You may have one of thes valves with the big black handles, the valve itself is grey. The thing is.... it seems that they work.... but they don't. Actually the outside turns, but inside they are stuck. open them up and deblock it.
If it is not that... get your hand and arm ready for serious ****. The pipes are blocked with chalk, if that is not the case anyway, together with the valves. Yes, i know, it is a nice job but someones gotta do it.. and this time it aint me!

[Hud3]

Another thing to check is the air vent to the holding tank. It can get clogged in at least two ways: from the inside if you flush too much into the tank (a wad of toilet paper makes a pretty good stopper), and from the outside if a mud dauber wasp or some other insect builds a nest in the vent opening. If the vent is clogged, you're creating a vacuum in your tank when you pump it out. It might not collapse, but don't chance it.

To clear the clog, get a toilet plunger. Remove the handle and place the rubber plunger over the vent, on the outside of the hull. Press a water hose on the hole where the handle was, and blast the vent with water. If that doesn't work after a few tries, you'll have to figure out how to remove the nut attaching the vent on the inside of the hull, so you can remove it and clean it and the tubing.

Good luck!

[Pblais]

I think Hud has your answer. without a vent you can't replace the contents with air as it pumps out the waste. You may also have a clogged deck pump out line too.

Vents also allow the waste to oxidize aerobically. This reduces smell and in an oxygen poor environment waste can be a serious problem. This is also the reason some people get sprayed when they open the pump out cap. Pressure builds in the tank and makes fountain. Always best to open them a few turns to hear if air is rushing out. It too indicates a clogged vent line.

If the pump just labors and no air or waste is coming out of the tank it means there is indeed a vacuum.

[Alondra]

Ok... bets are on! The valve and hoses or the air outlet...??? :-)

[Hud3]

You're on!

A round of Killer Bees at Sunshine's beach bar, next time you're in Nevis. Or, Kingfisher beers next time I'm in Goa!

[B00ST]

Very Interesting - I was getting a bad smell on a trip the other day and decided to replace the filter...When I pulled off the old filter, it was wet (and dripped on me - yuk)

So, as an experiment - what if I went to pump out and disconnected the filter line at the filter when I pumped....? I've ran a hose (water) through both in and out lines of the filter and had water shoot outside the boat and into the tank....but if the new filter and/or old filter caused and issue then that would make sense.

By the way...if its the case...I will be sending you drinks!!!