Vacuflush problems

G

GeoffG

New Member
Sep 2, 2015
10
Florida
Boat Info
05 Sundancer, 39
Engines
Cummins QSB 380HP
Having problems flushing the vacuflush head on our 39 dancer, 05 model. Worked perfectly for a while and then started refusing to flush. Green (has vacuum) light stays on when this happens. Managed to clear it a few times, by repeated plunging etc and all appeared to be good, but then it plugged again, despite no solids having been flushed. The immediate prior flush "test" was just water and it flushed with gusto! Next flush was just" liquid" and a bit of paper - and nothing! Vacuum pump is not running and green light stays on. When the head was working properly, it only took may be 20 seconds to restore the green vacuum light, so the pump appears to be working as it should. So far, repeated plunging refuses to clear it.

I would assume the I just have to continue working on clearing the clog except for one thing. Each time I have pumped out the head tank, (we have only owned the boat for a few months) it seems like very little "material" has been removed from the tank. The tank looks like it is a two piece tank, nothing like the rectangular box tank on my previous boat. So I am wondering if I have an internal plug in the tank which is causing the problem.

I do not know how full the holding tank is, as I cannot see through the stained plastic tank sides and the three level probes do not register anything. (Separate question, how do I get these to read? The probes appear to be glued in to the tank). But we pumped out the tank again after this problem occurred yesterday, and again little material was removed, implying that the tank is empty. Inserting a hose in to the pump out vent enables a few gallons of water to be back added to the tank, without any problem - and then pumped out again - also without problem. I saw no signs of a leak when doing any of this - ie. we do not appear to be losing suction on the pump-out hose pipe.

Any help or advice on this issue would be very much appreciated as my wife is really "peed off" with this problem (pardon my pun!)
 
The pump worked fine prior to the "plug" and only ran for 20 seconds or so after a flush. Now the green light stays on - indicating we have vacuum and the vac pump is not running.
 
This happened to me. It will pump up but you have a clog towards the tank after the vacuum pump. What I did and have done is shut the water supply off the stick a garden hose full strength down the head W/ it pumping at the same time. Presto!!! Fixed That is what it sounds like that you have.
 
Update - got the plug cleared by using a more powerful concertina type plunger. Still concerned that we have an underlying problem though, as the plug occurred (again) after just flushing pee and paper! I also think we should be removing much more material from the holding tank when we pump out - seems like not much is removed at all. We have had vacuflush systems previously, so I have an idea what to expect.

Vac pump and toilet seals all appear to working perfectly again and we have good vacuum at the toilet - for now! Only takes 25 seconds to re-achieve vacuum after a flush.

I will next try to flush the holding tank with water and detergent - leave it sit for day or so and then pump out again. May be that will help to get my level probes working again as they do not read at all now. Any other thoughts on this issue?
 
Did you know that if sewage is left in the tank it will solidify and will never come out with typical dock pump outs. Never leave sewage in a tank longer than 2 weeks. IMO I would focus on plumbing between pump and holding tank. If that is clear move forward to pump assembly-pressure switch and DB Valves....
 
Sounds like a clog in the line from the head to the vac-generator.

Not any fun but, I'd disconnect the hose at both ends and snake out. Replacing it probably is much more difficult due to where its run.

As far as not removing much black water....I'd get someone else to check it out who has the same system and get an opinion.
 
Well it appears that the problem is solved. I did get the line plug cleared out a while back - with some difficulty - and the head worked as it should and developed vacuum quite quickly, but it still seemed like I was not getting much black water out of the tank, as noted previously. So I re-built the vac pump with new valves and also new piston, though the old one looked fine. After re-build, I still generate vacuum in about the same time period, though the suction appears to be increased. When we pumped out on the weekend, we removed what I would call a normal amount of black water from the tank. Don't understand how the vac pump could affect the removal of black water from the tank, but whatever the reason, we seem to be in good shape now. Thanks for the help on this.
 
Update on the line plugging problems we experienced, which I hope may help someone else having similar issues: After the re-build of the vacuum pump etc. it appeared that our plugging problems were resolved for a while, but then we had more issues, culminating in a plug that just would not free, despite very aggressive work with a plunger. I then tried to clear it with a 15 foot long drain "auger", but no luck. I deliberately bought a 15 foot auger, knowing that I had about 25 feet of pipe to the rear vacuum/holding tank, as I did not want to risk damaging the duck bill valves. I then realized however, that the pipe in to the tank did not pass directly in to the vacuum pump, but instead was direct in to the vacuum tank, via a 90 degree elbow. So I attempted to remove the pipe from the tank, with the intention of "auguring" from the other end. I could not get the pipe off the elbow in the tight space, as it was "welded" on to the elbow, so I removed the pipe and its elbow from the tank. Surprisingly, it is installed with only a push fit through the Vinyle (?) grommet. I expected that to hold vacuum that a threaded fitting would be required, but no, just a friction fit. I fairly easily removed the elbow and the short piece of pipe beneath it and there was my problem! A plug in the pipe, just below the elbow. Cleaned out the plug, re-installed the pipe/elbow and we were back in business!

Later, thinking bout how the plug came to occur in the straight piece of pipe, it occurred to me that the pipe/elbow, when inserted all the way in to the tank, must be very close to the bottom of the tank, thereby creating a potential obstruction for a "chunk" of TP etc. I therefor plan to crawl back in to the stern corner of the boat and back out the pipe about an inch or so, so as to leave a greater gap between the bottom of the pipe and the bottom of the vacuum tank. I will probably also cut the pipe at an angle as well, to further ensure free flow of material. Hope this info helps to avoid the same frustrating sequence of problem for someone else.
 
GeoffG said:
Inserting a hose in to the pump out vent enables a few gallons of water to be back added to the tank, without any problem
Click to expand...

We also have a Vacu Flush system, and although I see that you have resolved your issue successfully, I would not recommend that one should insert a hose to run water into a vent on the system.
We have a holding tank vent filter on our vent line that we found to be clogged terribly because the charcoal was wet when we first got the boat, and the toilet would not flush until all the wet charcoal was cleared from the line and the vent filter replaced.
 
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