Pumpout Problems

[mpl239]

I cannot pump out the front head on a 2003 two cabin 393. This is a new boat to me. First effort to clean out front tank. This head has an electric toilet. To this point in time, my research has not generated similar problems, other than vent line plugged with no discussions of the other symptoms.


Observations:

Flushing the toilet sends fluid to the tank, with air gurgling in tank

With the Y valve in the tank fill position, fluid back flows into the toilet after flushing

With Y valve in overboard position and the seacock open the toilet pumps out, but some back flow, less than the tank back flow

Tank is full, fluids have leaked out of the vent

Nothing gets sucked up in the clean out process, I can see
brown water in the vacuum line sight glass, but nothing goes down the hose

Tried to squirt clean water through the deck fitting, it blew back on hose holder (me)

I can drizzle water into the tank slowly through the deck filling without filling the tube

Head had a strong sewage smell

Vent line appears to suffer some sort of partial plugging, preventing the vacuum evacuation

Tank evacuation tube is somewhat clear; drizzled water does not fill it up

I suspect the full tank is a real problem, just waiting to happen


Thoughts:

Try to evacuate some fluid from the deck hole using a 1" dia. pvc pipe attached to the vacuum hose (start with about a 3 ft pipe) to allow venting around the pvc; all of this to generate room in the tank to try back flushing the vent line with water

I am not wanting to open the inspection port on the tank - besides the vile odors and cleanup issues the waste can cause nasty things to happen to your body


Request:

I would like to go back down to the boat with the proper tools and supplies to cover the various possibilities, to fix this issue in a single effort, defining work that can be done at my berth and at the fuel/cleanout dock
Any suggestions, thoughts or things not to do would be greatly appreciated to resolve this crappy situation

Mike

 

[Peggie Hall HeadMistress]

Your holding tank vent IS blocked, and is the source of all your problems...

1. it's not letting air displaced by incoming flushes escape, so the system becomes pressurized, creating backpressure that's not only preventing flushes from getting anywhere, but pushing them back into the bowl.

2. it does not allow air into the tank to replace contents as they're being pumped out...causing the pump to pull a vacuum that won't allow contents to be removed. Suction from an especially strong pumpout CAN implode a tank!

So the first thing you must do is clear the tank vent. The vent thru-hull is the most common location for a vent line blockage...use a screwdriver blade, ice pick--whatever works--to clean it out...if there's a screen in it, knock out the screen...screens cause more problems than they solve. If the thru-hull is the only blockage, sewage will most likely start to flow out the vent. If not, open the deck pumpout fitting to relieve any pressure, then remove the vent line from the tank and clean out both the vent fitting on the tank and that end of the vent line. After you put them back together you SHOULD be able to pump out the tank.

We can deal with any additional problems after you've solved this one.

 

[Gunni]

You will need a 3/4" dip tube and plumbing fitting to fit that dip tube up to the pump out nozzle. Alternatively take a displacement pump (diaphragm) with hose, bucket, and dip-tube to the boat. What you want to do is extract pump enough fluid through the deck fitting to work on the vent. Then you need to push water in the vent shell on the hull. You will probably need to extract fluid from the deck fitting / push water back up the vent line a number of times. When you know you are getting flow through the vent, do a pump out and clear the tank. Do several vent flushes with pump-out dock water. Fill the holding tank and extract that also. Do it twice.

 

[Ron20324]

I'm surprised no one has yet suggested to install a larger vent line- and do away with that small OEM fitting on the hull.

 

[Peggie Hall HeadMistress]

One step at a time, Ron...one step at a time.

 

[Rick I]

It is not uncommon for the pick-up tube inside the tank to come adrift.

 

[Maine Sail]

Bene's are rather notorious for the blue (usually blue but brown by the time you find it) pick up tube falling off inside the tank. Use a coat hanger to confirm the tube is there or not. If not, put a garbage bag over your arm, or TWO, reach in and find the pick up tube. Now stuff it back into the pick up and suck the tank out. Once you do that, correct & fix the lame Bene pick up tube!!..:cussing:The last one of these I diagnosed was on a First 36.7 a few weeks ago. The owner, clearly a really, really good guy, did the deed for me.....

 

[Gunni]

I believe the deck fitting on this model is plumbed to the bottom of the waste tank, there is no drop tube in the tank. Which is good news for snaking a dip-tube down from the deck fitting and lowering the waste level in the tank. In addition to the approach I described earlier, I have also remedied this over-fill problem by an extended work session at the pumpout station; placing a suction on the deck fitting while forcing water into the vent.

 

[Ron20324]

My 2006 B323 is also hosed from the deck to the bottom of the tank. You said you saw only brown water in the pumpout hose sight glass. Everything in the tank may well have been "liquified" - even the paper-by the time you pumped out. Mine's always all liquid(or close to it), and I pump every other week.

 

[Rick I]

I believe the deck fitting on this model is plumbed to the bottom of the waste tank, there is no drop tube in the tank. Which is good news for snaking a dip-tube down from the deck fitting and lowering the waste level in the tank. In addition to the approach I described earlier, I have also remedied this over-fill problem by an extended work session at the pumpout station; placing a suction on the deck fitting while forcing water into the vent.

AFAIK the 393's have a pick-up tube inside the tanks for pumping out. As has been noted earlier they are notorious for falling off. The deck fittings are plumbed to the top of the tank.

 

[Gunni]

AFAIK the 393's have a pick-up tube inside the tanks for pumping out. As has been noted earlier they are notorious for falling off. The deck fittings are plumbed to the top of the tank.

I would be very happy to NOT have a waste tank bottom fitting . But I in fact have two, one in a forward head identical to the 2 cabin OP's 393 head. The remedy remains the same, he will need a dip-tube to snake into the waste tank (either top fitting, or bottom - connected to the pump out nozzle or a displacement pump.

 

[Peggie Hall HeadMistress]

Have we determined that his tank is one that has a dip-tube? From what I'm reading, some Benes do, some have the pumpout fitting at the bottom of the tank. Unless his IS one that has a dip tube, cleaning out the vent thru-hull should result in a geyser out the vent that should relieve the pressure enough to let the tank be pumped out via the deck pumpout fitting.

 

[Paul Mermelstein]

I have the same model, a B393, as in the original post. We have two heads. On my boat, each head has the deck fitting for pumpout plumbed to the bottom of the tank. Each also has a macerator pump for evacuating the tank for offshore sailing, which is plumbed via a dip-tube which terminates close to where the regular pumpout hose connects at the bottom. On one tank, I had an experience where the dip-tube slipped down and blocked the hole for pumpout via the deck fitting.

So, if he has a macerator pump like mine, then he has a dip-tube for that, as well as the regular pumpout plumbed to the tank bottom. If it slipped down, that may or may not be the problem.

 

[mpl239]

Thank you all for the information. I shall clear the vent line and report back in a few weeks.

That J O B thing has me tied up for the next two weeks.

Mike

 

[Gunni]

Yes, this is one of the boat tasks that you really can't delegate to your boat tradesman. You just need to change into your disposable jeans, tattered long-sleeve t-shirt , snap on the gloves, pull down the face-shield, start a course of Keflex and get 'er done. Good luck!

 

[Syversens]

Before we got our wonderful electroscan I had this issue on a fateful morning. I learned that our pumpout was plumbed under the tank and our vent was indeed clogged and not knowing/thinking too much about it I released pressure from the pumpout. Geyser is what followed and good thing we were not in the harbor when this happened. I did find that mostly what came out was the blue stuff I'd put in there to "deodorize" the tank, which was just filling the hose and not doing anything.

Anyways, lesson learned as admiral immediately ordered looking into options and we got electroscan 5 years ago. Rumors has it that my waters in Puget sound possibly will be no discharge, even treated, and when that happens I'm moving to composting toilet.