Vacuflush won't pressure up

My vacuflush was cycling on about every two minutes, but was creating a vacuum and the toilet would flush. I'm pretty familiar with this system, I've had issues with it before.



Toilet is holding water, so I assumed it was a duckbill valve.



Changed the two duckbills in the outlet line. No improvement.



Changed the two duckbills in the inlet line, now it won't create a vacuum at all, the pump just runs.


Disassembled and reassembled several times using Vaseline. No fix.


Used the shaving cream trick, nothing is being sucked in that I can see.


I'm in the Bahamas with somewhat limited parts and worried this could be a trip breaker (we just got over on Wednesday).



I do have a replacement bellows for the pump, how would I diagnose that?

Step two.



Changed the bellows, I don't have a spare set of o rings but they looked fine. I greased them with vaseline before reinstall.


Took the toilet off of the base, cleaned up the gaskets under it and reinstalled.


I'm now getting some pressure when I flush, but not as much as normal. Pump just runs and runs.


Could it be a clog possibly?

Clue 3.


Took off the inlet hose. Put my hand over the inlet pipe and turned on the head. It sucks pretty hard against my hand but won't turn off. Water is still sitting in the hose between the head and the inlet to the vacuum generator.


Blew through the inlet hose and the toilet bubbled, so it doesn't seem like there is a clog in that section.

The trouble-shooting guide lists all the possible causes and cures for no vacuum...it's in the owners manual...also in my book. If you don't have either one, send me a PM that includes your email address (no way to attach anything to a PM) and I'll send it to you.

If none of the probable causes and cures in the trouble-shooting guide solves the problem, it's time to contact Dometic/SeaLand tech support. The phone number for their US plant in Ohio is 800-321-9886 They'll give you the name and contact info for the nearest authorized service center who can walk you through the problem and solution on the phone.

--Peggie

I had a leaky diaphragm on the pressure switch on the tank. Can you try the shaving cream trick there? That won't be good for you out there in the boonies away from parts supply.

This is not your problem, but I had a clear circular light cover pop off and bounce its way into the toilet unseen by anybody - the lid is always down now. It fit PERFECTLY over the small end of the funnel in the toilet and nobody could see it in there. We spent forever trying to figure out why the water would not suck out of the bowl. At first, we did not even know for sure there was vacuum generated in the system and broke a thing or two figuring that out.

Another vacuflush nightmare. Seems there is a new thread every month. Ditch the vacuflush and get a trouble-free Marine Elegance electric head. In eight years following this forum I have never seen a problem with a Marine Elegance.

!st fix is always flush a bunch of water.

Anytime I have any issue with my Vacuflush I just fill the bowl up with water almost to the top and flush away. This cleans out any debris that can be fouling up the duckbills or any other parts. I have had my Vacuflush for 9 years now and changed the duckbills once when I was noting longer pump down times. Other than that it has worked flawlessly. Also the plain water will help your pump push and pull better clearing any blockages. If it will pump that much water then i would say there are no blockages.

The Vacuflush system is not complicated. Just a diaphragm pump and a pressure switch.

A blocked pump discharge will misshapen the duckbills or turn them inside out. Did the old duckbills look deformed when you replaced them?

Also make sure the pressure switch is tight.

We had a worn switch and it gave those symptoms as it wasn't moving enough when pressurized to break the connection. I ordered a new one and it solved the issue, so I then ordered a spare as well.

Until we got the new switch we just turned off the breaker . Turned it on before we wanted to use the head.

catalinajack said:

Another vacuflush nightmare. Seems there is a new thread every month. Ditch the vacuflush and get a trouble-free Marine Elegance electric head. In eight years following this forum I have never seen a problem with a Marine Elegance.

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You beat me to it...

I'd be happy to replace my vacu flush with a different head. In fact, at the next major repair, that is exactly what I'm going to do.


In the meantime, this issue turned out to be a case of dumassery on my part. I put one of the new duckbills in wrong.


It's still cycling every 5 minutes, but at least it is flushing now, it should make it through the trip. In the last six years I've spent over $1,000 keeping this vacuflush running. Two new bellows, a new pump motor, new vacuum tank, multiple duckbill valves, a toilet base, bowl gaskets, a pressure switch, it just goes on and on. And now I don't trust it anymore. It's my least favorite system on the entire boat.


I had a basic raritan sea era on our old boat and never touched it in 8 years of use.

I had a similar issue. Ended up being a small hole in the main pipe. Replaced it, works fine. Get Peggie's book and it will guide you.

We just put in a Raritan Marine Elegance this winter. Love them. Put one in a previous boat. Unfortunately it looks like this summer we won’t really be able to use it with the virus. Highly recommend the ME head.

Just to update this post, here is where I currently stand with this head.


During the course of our month in the Bahamas the head would cycle every thirty seconds. In order to save wear on the pump and bellows (and so we wouldn't have to listen to it) we would turn the breaker on prior to using the head, then turn it off after we were done.


Once we got home I began to seriously dig into the issue to see if I could get it fixed. Just as a reminder, the vacuum tank, bellows, duckbills, pressure switch and pump motor are all 18 months old or less. No water was leaking from the toilet.


Here's what I did:


Step one. Took the inlet hose off of the vacuum generator, then jammed a wet tapered plug into the inlet. Powered up the unit. It held pressure for 6 minutes, which I figured was pretty good considering it had a plug in it.


Step two. Put the hose back on the inlet. Removed the toilet from its base. Cleaned up the urine that always runs out of the toilet every time I remove it, no mater how many times I flush it or how I clean it. Removed the base itself which gave me access to the funnel. Considered replacing the funnel, but Mainship didn't leave enough slack in the hose to reach the hose clamp on the bottom.



Jammed a plug into the funnel and powered up the system. It held pressure for 4 minutes. Much better than 30 seconds, so I figured the issue was thankfully above the funnel.


Replaced the Floor Flange seal ($15) and reassembled everything. Turned the system back on. It held pressure for 30 seconds.


Step three. Take the toilet off again. Yes, more urine on the floor. Replace the ball valve kit ($75) on the advice of Environmental Marine. Even though the toilet was holding water, there is a shaft in there that has two O rings on it. Those O rings can go bad. I used lots of silicone grease on their recommendation. The shaft on my toilet looked fine, the O rings were both there and there was some (not a lot) residual grease.



Powered up the system. It now holds pressure for 6 minutes, and pressure up in only 6 or 8 pump cycles, whereas before it would take 30ish cycles to pressure up.



So, much better but still not fixed.

6 minutes of vacuum hold after step 1 and same after steps 2 and 3 suggests to me that the issue was not improved much by steps 2 and 3, although the shaft kit replacement was the final step in my own resolution of leaks. Duckbill and the vacuum switch are my candidates outside of some pipping issue. My VF will hold vacuum for days now.

rgano said:

6 minutes of vacuum hold after step 1 and same after steps 2 and 3 suggests to me that the issue was not improved much by steps 2 and 3, although the shaft kit replacement was the final step in my own resolution of leaks. Duckbill and the vacuum switch are my candidates outside of some pipping issue. My VF will hold vacuum for days now.

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Hey Rich,


The 4 minutes of hold after step one was isolated to the vacuum generator, I put the plug directly into the tank's input to eliminate any leaks that were "above" the vacuum generator. At that stage, the entire system, from toilet to vacuum generator outlet, would only hold pressure for 30 seconds.



I replaced all four duckbills in July of this year. The Vacuum switch was replaced by Environmental Marine in their shop 18 months ago, it could be the issue, but it seems unlikely.


The guys at Environmental Marine who have been helping me through this think it is maybe a O ring somewhere on the Vacuum Generator. The next time I go down to Ft. Lauderdale I'm going to bring the generator to them to test on their bench again.


I think I had two issues, the ball valve shaft and some other as yet undiscovered issue on the generator itself.

I agree, it is in the vac gen unit. Be very interested in what you find out. Thanks for updating us all on this.

Knocking on wood here. Other than replacing duckbills twice in 14 years of ownership, no problems at all, well, except the time a guest flushed a certain item that shouldn't have been flushed and plugged the holding tank, but can't blame that on Vacuflush : (

Max Simmons said:

Knocking on wood here. Other than replacing duckbills twice in 14 years of ownership, no problems at all, well, except the time a guest flushed a certain item that shouldn't have been flushed and plugged the holding tank, but can't blame that on Vacuflush : (

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Your day is coming. You can rest assured of that.


Actually working on Vacuflush systems is really easy. It's pinning down the issue that is the problem. Every single O ring, seal, gasket, duckbill, plastic fitting, screw head etc. from the toilet to the tank outlet is a potential point of failure. And some of the parts are outlandishly expensive.

Somewhat off topic but one maintenance trick I learned from an experienced tech in Nanaimo, B.C. was to occasionally put a little vegetable oil in the bowl and flush. He contended that it kept things from hanging up and help keep O rings, duckbills and the like a little more flexible. I've been doing that for years and have not had a VF issue. (Replaced the ball valve gasket as a matter of maintenance but thats it.)

I had a small tear in the bellows that drove me crazy. Might want to remove and inspect it. Also once had a set of duckbills that were slightly misshapen when newish (stored a long time since new) and they wouldn't hold vacuum. Since you installed one backwards, perhaps it is damaged.

mike66 said:

I had a small tear in the bellows that drove me crazy. Might want to remove and inspect it. Also once had a set of duckbills that were slightly misshapen when newish (stored a long time since new) and they wouldn't hold vacuum. Since you installed one backwards, perhaps it is damaged.

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Thanks Mike. I replaced the bellows last month when I changed out the duckbills. That's a good tip on the duckbills, mine were only a few months old but anything is possible.