Vacuflush issue

I have learned a lot already reading posts about a Vacuflush system. Here is my issue: New pump and it runs continuously and pulls water VERY slowly(30 minutes or more to pull a 1/2 bowl of water). Service manager thinks there is a vacuum leak in vacuum tank. I think the intake pipe to pump is mostly blocked but water is still getting to pump. It does create some vacuum if it runs long enough. Turn on pump as needed, do not leave on. Water heater in front of vacuum tank so will be a big event to pull the tank. Have used plunger, helps a little. Thoughts. Thank you.

Horseplay said:

I have learned a lot already reading posts about a Vacuflush system. Here is my issue: New pump and it runs continuously and pulls water VERY slowly(30 minutes or more to pull a 1/2 bowl of water). Service manager thinks there is a vacuum leak in vacuum tank. I think the intake pipe to pump is mostly blocked but water is still getting to pump. It does create some vacuum if it runs long enough. Turn on pump as needed, do not leave on. Water heater in front of vacuum tank so will be a big event to pull the tank. Have used plunger, helps a little. Thoughts. Thank you.

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The highlighted portion tells it all.

At least one problem is that you have a seal leaking in the bowl. This is quite probably the seal between the ball and the bowl. The new seal takes maybe 30 minutes to replace.

You might and probbably do have other problems, but this is for sure one.

I put water in the bowl after I finally get the water down to bottom of toilet, water stays in bowl while pump is running for quite a while longer. In my mind the pump should be able to pull the water out of the toilet without a vacuum. After I get the water to move properly then I will look for vacuum leaks. Probably have a couple of problems as suggested. Peggy brought up the holding tank vent being plugged in a post. I don't know where that vent is but I am going to open my tank pump out and see what happens. Thank you.

There are at least 4 places around the pump and head where leakage can occur, the bowl mounting base being one. A vacuum gauge and suitable rubber stoppers can be purchased from Sealand to do a leak down test. Or hire a boat mechanic who has one to isolate the problem area.

Sounds like there is no vacuum at all. The bowl should vacate almost instantly when flushed. The vacuum gauge they sell is extremely helpful in pin pointing the source(s) of the problem when used per the manual's trouble shooting guide.

Has the holding tank been pumped out, by the way?

The usual suspects are the duck bill valves in the pump. They can be distended by using a plunger, which is almost always a bad idea for these systems. There are a few other spots which can also be culprits, often times where a hose connects to something else.

A properly configured VF system is about the most reliable flushing toilet you'll ever own on land or sea. We lived aboard full time with three of them for several years, and once I re mediated one that was installed incorrectly, maintenance was virtually nil despite heavy usage by owners and guests.

These are high maintenance toilets, and it sounds like you are overdue for a complete rebuild. There is a rebuild kit available and to that add a new bellows. While everything is apart check for calcium buildup in the hoses.

Vacuflush was state of the art ten years ago, but today there are better (e.g.: Raritan Marine Elegance)

Rossland said:

These are high maintenance toilets, and it sounds like you are overdue for a complete rebuild. There is a rebuild kit available and to that add a new bellows.

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Really. Not for me.

Anyway, for the OP, do a leak down test once you are sure hoses aren't blocked.

So it sounds like there needs to be vacuum to move the water to the vacuum tank. It will not pull water to it without starting with a vacuum?

We have had our boat for 22 years with a Vacuflush and it has been great, very little maintenance during that time. Just a couple of bowl seals but we change the duckbills every couple of years, all easy to do. Sounds like it needs new duckbills in the vacuum pump (all four bills), I have attached the troubleshooting guide that is found in the forum library.

Thank you rochepoint.

Horseplay said:

So it sounds like there needs to be vacuum to move the water to the vacuum tank. It will not pull water to it without starting with a vacuum?

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Yes, first let it build up a vacuum before you flush. If it won't build or hold a vacuum, then refer to the troubleshooting guide that Rochepoint posted. Items 1, 8, 11, or 17 are mostly likely the cause.

Horseplay said:

So it sounds like there needs to be vacuum to move the water to the vacuum tank. It will not pull water to it without starting with a vacuum?

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Think about it like this...

There is a pump.
In between that pump and your head is a tank.
The pump sucks whatever is in the tank out and in doing that creates a vacume.
When you flush the head all you are doing is opening a valve in the bottom of the toilet bowel.
The vacume sucks the contents of the bowel into the tank

Then the process repeats itself with the pump sucking out the contents of the tank.
The discharger side of the pump goes to your boats holding tank

The things called "duckbills" are one way valves. They are positioned on the inlet and outlet side of the pump. The two on the inlet side (the tank side) hold the vaccum described above. The two on the outlet side keep effluent from draining out of the holding tank back into the pump.

Ince you get your head wrapped around how the system works, it's easy to troubleshoot.

So if my head is full of water and the hose going to the vacuum tank is full of water and my new pump will not pull the water.... my logic says that I have a obstruction or I am sucking air in the vacuum tank. Correct or off? Thanks.

Horseplay said:

So if my head is full of water and the hose going to the vacuum tank is full of water and my new pump will not pull the water.... my logic says that I have a obstruction or I am sucking air in the vacuum tank. Correct or off? Thanks.

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Yes, correct.

If your tank side duckbills were leaking allow that would also act as you described