VacuFlush toilet questions

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suntansailor

Veteran Member
Joined
May 21, 2017
Messages
69
Location
Sint Maarten DWI
Vessel Name
Au Naturel
Vessel Make
2000 Mainship 390 Trawler
I have a 2000 MS 390 with a VacuFlush toilet...worked well for the 17+ years, but quite noisy in the middle of the night when others are sleeping.

My vacuum 12v motor finally died, thus no toilet function.

The question is has anyone retro fitted the new "quiet motor kit" from VacuFlush Dometic/Sealand?

What kind of task was it to do?

It is a challenge to get to it, as that hatch at helm floor is kind of small for us big guys...do you take the entire generator vacuum assembly off the pressure tank, and then install the new bellows, quiet motor, and new 4 duckbills, and then reassemble it back onto the pressure tank?

It says it comes with directions, but I am awaiting the package still here in the Caribbean, so just wanted forum input/expertise so to know what to expect in workload...anyone done this?

Also having no confidence in the 4 light level gauge for the holding tank and water tank with outside the tank copper foil level sensors, as it always shows 3/4 full.

So will install simple Wema/Kus analog gauges with in tank senders to see if that improves accuracy. Water tank sender will be easy install, but dread the holding tank sender install where it is located...once completed I will update with pictures.
 
Also having no confidence in the 4 light level gauge for the holding tank and water tank with outside the tank copper foil level sensors, as it always shows 3/4 full.
This type of holding tank sensor is the best I've ever had and I've had them all! I assume your holding & water tank is not metal and if not, I question the installation. :blush:
 
While my pump is separate from the vacuum tank, I would still recommend the following. I would remove the pump and completely rebuild it. The rebuild is much easier than it sounds. It basically consists of replacing the diaphragm, 2 orings, in your case the motor, and the 4 one way valves. Having done it twice, I would estimate I could do it from removal to reinstallation in less than 2 hours. First time might take you 3 hours. Fully rebuilt, the pump should function for many years with only changing valves every few years.

Ted
 
I installed the quiet motor kit on both of my Vacuflush units, easy peasy, and it really does quiet down the pump sounds.

Access is a big issue. Personally I found that it was easier to remove the vacume pump/tank assembely and do the work outside the boat on my fish cleaning table. (which I subsequently bleached :blush: )

I had never worked on a Vacuflush before and found the job easy to acomplish. Having the unit out on a bench also demystified the thing, increasing my apreciation of it.
 
I installed the quiet motor kit on both of my Vacuflush units, easy peasy, and it really does quiet down the pump sounds.

Access is a big issue. Personally I found that it was easier to remove the vacume pump/tank assembely and do the work outside the boat on my fish cleaning table. (which I subsequently bleached :blush: )

I had never worked on a Vacuflush before and found the job easy to acomplish. Having the unit out on a bench also demystified the thing, increasing my apreciation of it.


This.


I'm not sure how the access compares in your 390 vs my 400, but I did this job a few months back. I pulled the hoses then removed the screw in each of the four "legs" that hold down the tank. Remove the entire tank and then put it on the bench. There are some good YouTube videos on the rebuild, it's easy once you can get to everything.
 
VacuFlush toilet fix

Thank you all for the feedback...I will follow the advice to pull out the assembly and work on it out of the below deck. I believe to "kit" I ordered comes with the new bellows, o rings, quiet motor, and hardware. I had also order the 4 duckbills previously for maintenance purposes. Now I am hearing that once this rebuild is complete, the system should be better tan before.

And yes, I am a bit hesitant on attacking this, as I have no previous experience on this style of toilet...but assume after I clean my hands up from the rebuild I will be sort of an expert...I hope. Thanks again to the forum members for their input.
 
Also having no confidence in the 4 light level gauge for the holding tank and water tank with outside the tank copper foil level sensors, as it always shows 3/4 full.

So will install simple Wema/Kus analog gauges with in tank senders to see if that improves accuracy. Water tank sender will be easy install, but dread the holding tank sender install where it is located...once completed I will update with pictures.


A bud with our same boat model installed the foil sender, says it works fine for him. Dunno what brand, or what the gauge (display) is.

We have the WEMA/KUS senders, both fresh water and holding tank. Easy installation... although we had to cut an access for the much longer water tank sender.

They both work fine; helps to do a Mark I* eyeball comparison of tank level to gauge display while you have visibility to the tanks.

The holding tank sensor can occasionally get crudded up with uric acid crystals... so we have two sensors. Out with the old, in with the new takes about 30 seconds. Re-making the electrical connections with male/female spade quick-connectors (or similar) takes about 15 seconds. We usually put the "used" sensor in a container with muriatic acid (or similar), let it soak itself clean, store it for the next swap. We usually get 2-3 years out of each before swapping.

In a pinch, a major THWACK! on the tank top with a rubber mallet will often free up the sensor enough so it'll work 'til you get a more convenient time to deal with it.

-Chris
 
And yes, I am a bit hesitant on attacking this, as I have no previous experience on this style of toilet...but assume after I clean my hands up from the rebuild I will be sort of an expert...I hope. Thanks again to the forum members for their input.

I would describe the work as simply replacing parts with a little cleaning in the process, plug and play.

Ted
 
Thank you all for the feedback...I will follow the advice to pull out the assembly and work on it out of the below deck. I believe to "kit" I ordered comes with the new bellows, o rings, quiet motor, and hardware. I had also order the 4 duckbills previously for maintenance purposes. Now I am hearing that once this rebuild is complete, the system should be better tan before.

And yes, I am a bit hesitant on attacking this, as I have no previous experience on this style of toilet...but assume after I clean my hands up from the rebuild I will be sort of an expert...I hope. Thanks again to the forum members for their input.

The only problem I found with Vacuflush was my lack of knowledge regarding how they work. Once I got over the hump knowledge wise I realized just how simple a system it is.

A simple diaphram/bellows type vacume pump sucks the vacume tank “dry”. Remember the tank is on the suction side of the pump. The pump has a in series pressure/vaccume switch. On the pump the suction side duckbills are what holds the vaccume. The outlet side duckbills keep effluent from backflowing into the pump. Quite simple once you get the concept down in your head.
 
A simple diaphram/bellows type vacume pump sucks the vacume tank “dry”.

Not exactly, Ken... It's accumulated "vacuum," not the pump, that sucks the flush out of the bowl THROUGH the vacuum tank, nothing should ever be IN the vacuum tank. And it's the loss of vacuum caused by flushing that turns on the pump. The accumulated "vacuum" only pulls the bowl contents TO the pump..the pump has to push it the rest of the way.

The vacuum pump has TWO functions: it suctions the air out of the plumbing between the toilet bowl and itself while simultaneously pushing the flush the rest of the way to the tank, treatment device or thru-hull. The vacuum tank has a switch and a sensor on it that starts the vacuum pump when there's a loss of "vacuum" (toilet is flushed or an air leak in the system) and turns it off when the correct amount of negative pressure has been reached. How long it runs after the pedal has been released depends on the distance from the pump to the bowl...the shorter the distance, the shorter pump run time. So if the distance from the pump to the tank is greater than the distance from the bowl to the pump, it's necessary to leave the pedal down to keep the pump running long enough to finish moving the flush all the way to the tank.

(This is from my article "VacuFlush 101"...I'll be glad to send the whole thing to anyone who wants it..just send me a PM that includes your email address (no way to attach anything to a PM).

--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein
 
VacuFlush toilet fix

All,

This weekend I just "rebuilt" my 20 year old VacuFlush toilet with the whisper quiet motor kit, new bellows, rubber rings, and 4 new duck bills. Messy job, and about 2.5 hours of my time going slowly. Follow the instructions step by step, and anyone can do it.

What a difference this new upgraded whisper quiet motor rebuild kit has made!

Suction is fantastic now, and honestly I thought I miss wired the motor as I did not hear it running on first test...too funny. When the floor access hatch at inside helm is in place, it truly is "whisper quiet"...figuring at least 3x quieter than old motor (20 years old). This will make the Admiral happy when 3am visits to head happen...

Hint: pull out old motor and bellows ensemble from the location, and rebuild on bench vs crouching all that time doing it all down below.

I highly recommend this upgrade!
 
Congrats on getting the job done!

Always nice to hear of success in something we don’t normally deal with and there is of course a good degree of satisfaction in the accomplishment...

Tacky question perhaps:

Can you give an idea of the cost involved? Dont really need the fix yet but like the idea of quiet.

-chris
 
All,

This weekend I just "rebuilt" my 20 year old VacuFlush toilet with the whisper quiet motor kit, new bellows, rubber rings, and 4 new duck bills. Messy job, and about 2.5 hours of my time going slowly. Follow the instructions step by step, and anyone can do it.

What a difference this new upgraded whisper quiet motor rebuild kit has made!

Suction is fantastic now, and honestly I thought I miss wired the motor as I did not hear it running on first test...too funny. When the floor access hatch at inside helm is in place, it truly is "whisper quiet"...figuring at least 3x quieter than old motor (20 years old). This will make the Admiral happy when 3am visits to head happen...

Hint: pull out old motor and bellows ensemble from the location, and rebuild on bench vs crouching all that time doing it all down below.

I highly recommend this upgrade!

Thanks for the info, I just ordered the kit from Environmental Marine for $250. This is for our guest head. Seems most of our guests don't like to pee on top of pee during the night! :D
 
Hello Peggy,
I’d like to take you up on the offer for the article VacuFlush 101. Please send to me at djewell@triad.rr.com.
Thanks,
Doug
 
Just curious, when we bought our boat almost 2 years ago, they had just rebuilt the vacu-flush toilet and I was wondering when it needs to be done again?? I have not taken the time to research the maintenance on these, I've been busy on other projects.

Thanks!!
 
Just curious, when we bought our boat almost 2 years ago, they had just rebuilt the vacu-flush toilet and I was wondering when it needs to be done again?? I have not taken the time to research the maintenance on these, I've been busy on other projects. Thanks!!


It shouldn't need any preventive maintenance except new duckbills every couple of years or when the pump starts to cycle between flushes for no reason. The troubleshooting guide in the owners manual includes every symptom, probable causes and cures that a V/F can develop. If you don't have an owners manual, send me a PM that includes your email address and I'll send you the troubleshooting guide. The VF has changed so little except cosmetically since Mansfield Plumbing introduced it in 1978 (Mansfield spun off their marine toilets division to SeaLand Technology in 1984) that the same trouble shooting guide works for all years, all models.


--Peggie
 
VacuFlush toilet fix

As an additional "honey do" item along with the VF rebuild, I was never happy with the Raritan LED liquid level light gauge for water and holding tank. It was 18+ years old, with corrosion, always reading 7/8 full in holding tank even after pump out, and 1/2 full to 3/4 full on water tanks even thought I could see the levels were not that.

So I decided to go "old school" with reed sending units and analog gauges. Could not find a unit that satisfied my enthusiasm, so created my own.

Ordered water and holding tank gauges from WemaUSA (now KUS)...cheap, and also ordered the tank senders as well. Quality SS product that should provide years of worry free service.

Installing sender in water tank simple, and used wiring from previous Raritan system. Installing sender in holding tank a challenge due to location, but got it done. Now with momentary ON switch, I get a tank reading and also wired the gauge backlight with switch so I can read it at night easily.

Simple wiring job, and now have confidence in levels again.
 

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Ordered water and holding tank gauges from WemaUSA (now KUS)...cheap, and also ordered the tank senders as well. Quality SS product that should provide years of worry free service.


FWIW...

We replaced our original circa-2002 WEMA plastic senders with their newer stainless steel versions, holding tank in 2007, and freshwater... ummm.... 2009 or 2010 or so...

Both work well. Every two or three (or 4?) years, the holding tank sender gets crudded up with uric acid crystals, so the "float" won't...

Easily cleaned by soaking in something like a mild dilution of muriatic acid. We got a second holding tank sender somewhere along the way, so I can do a quick swap and then clean the "older" one at my leisure.

-Chris
 
VacuFlush toilet fix

Hi Chris,

I like that idea. It was a true nightmare to install the sender flange into the poly tank when we did this change over. But the sender itself just screws into flange making it easier to take out and clean. I will follow your suggestion and secure a 2nd, so it should be easier on maintenance. Still, you have to be pretty small to get down there...

-Gordon
 

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