Another Vacuflush Question

So my master head VF won't flush.

I plunged it and after a half dozen good flushes the pump ran and sucks the water in the bowl away. I take my foot off the pedal and close the toilet. After a few seconds I press the pedal and no vacuum.

SO I plunge a half dozen times again and the pumps runs and takes the water again. But same result after I try and reflush.

I am assuming that my quick plunging is building the pressure to start the pump, but if I do not plunge no pump action.

Is this the duck valves?

Could be. Plunging is not something that you should ever do, it can invert the duckbills. So replacing them might be best place to start. Read the troubleshooting section of the Manual, work your way through the possible causes.

Insequent said:

Could be. Plunging is not something that you should ever do, it can invert the duckbills. So replacing them might be best place to start. Read the troubleshooting section of the Manual, work your way through the possible causes.

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Could be 9.b.

Looks like I have to disconnect the lines and see where it is plugged.

Just as well I am taking this week off.

Either way, get you a box of rubber gloves and a shop vac. You maybe breaking into the system. Good luck. And the Admiral wonders why I am so anal about the heads.....

Alaskan Sea-Duction said:

anal about the heads.....

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No pun intended!

menzies said:

No pun intended!

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none intended

If it is plugged then a likely suspect is 'female hygiene product' - any recent guests on board? The other common cause is not enough flush water. I ask people to give it what they think is more than enough then, add another 5 seconds to flush time. Watermaker on board so never gonna run out of water.

Insequent said:

If it is plugged then a likely suspect is 'female hygiene product' - any recent guests on board? The other common cause is not enough flush water. I ask people to give it what they think is more than enough then, add another 5 seconds to flush time. Watermaker on board so never gonna run out of water.

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No female products, and it is the master. We use the guest head for guests/day use. It is a totally separate system and working fine.

I will get the set of duck bills tomorrow and see what happens after I replace those.

If you're going to change the 4 duck bills anyway, spend some more time pushing fresh water with a splash of bleach for each bowl full through the system. Nobody ever said,"I wished I run less fresh water through the system before taking it apart."

Ted

YouTube video on the process.

Go to 3:30 to see the impact of toilet paper in your system!

It is probably the duck bills. We had the same issue with our master head. Unfortunately, in order to get to that vacuum generator, we had to remove the forward vacuum generator. By the time we got through THAT.....I said screw it, we are NOT putting those back in that space. A little advice from Peggy and we have two brilliant brand new electric heads on the boat and two vacuflushes in the garage.

Besslb said:

It is probably the duck bills. We had the same issue with our master head. Unfortunately, in order to get to that vacuum generator, we had to remove the forward vacuum generator. By the time we got through THAT.....I said screw it, we are NOT putting those back in that space. A little advice from Peggy and we have two brilliant brand new electric heads on the boat and two vacuflushes in the garage.

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That's an expensive solution! For trouble free VF operations there are just two rules: 1. only use special TP, nothing else whatsoever into the bowl. and 2. use lots, and I mean lots, of flush water every time, even just for urine.

Insequent said:

That's an expensive solution! For trouble free VF operations there are just two rules: 1. only use special TP, nothing else whatsoever into the bowl. and 2. use lots, and I mean lots, of flush water every time, even just for urine.

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Sure. No paper had gone into those while we have owned them. And had they been easily accessible we would have repaired them. However, the boat seemed to have been built around the vacuum generators and that was not a job we were ever doing again. So we have two full VF systems, less one functioning duck bill if anyone wants to buy them.

Thankfully mine are readily accessible.

The guest is directly under a hatch by the guest cabin. The Master is under the master bed. The bed lifts up and there is storage and an access panel on the bottom of the storage.

I did tell my wife that tonight and she went "ewwww, do you mean we are sleeping above sh*t?:

Get a box of rubber / latex gloves at Harbor Freight, put two or three gloves on each hand....and put a garbage bag in the shopvac. Disconnect the inbound hose from the vacuum generator (as the hose comes off the fitting, clamp your palm over it, then pull the glove off your hand so it inverts over the end of the hose, duck tape it. Use the shopvac to collect any spillage. Now do the outbound hose the same way. Disconnect the two wires to the switch /motor. Now unscrew the generator and lift the entire unit onto the dock to work on the duckbills. Always a good time to flush the generator, as I found one had a collection in the bottom. It's much easier changing the duckbills outside the boat.

OK, so I got my tools ready, rubber gloves, duckbills, mouth and nose protector etc.etc.

Went down to the boat, and tried the breaker one last time. When i turned the breaker on the vacuum pump ran for the usual 30-40 seconds. I went to the head and pushed the pedal and the toilet flushed away with a strong vacuum. When I released the pedal the pump did not run and no "next vacuum" was created.

Is it the switch?

Searching on line all of the issues created by a faulty switch seems to mean the pump running all the time. Could a bad switch also cause the pump not to run at all, and maybe after leaving a while the switch spring moves to indicate no pressure?

Stumped in JAX.

Could be switch, dead spot on motor, could be a loose crimp connection somewhere. With breaker on push pedal to verify no vaccum. Then jump the switch to see if the pump starts. Still no suction, check for positive and negative from power feed through switch to pump.

Ted

O C Diver said:

Could be switch, dead spot on motor, could be a loose crimp connection somewhere. With breaker on push pedal to verify no vaccum. Then jump the switch to see if the pump starts. Still no suction, check for positive and negative from power feed through switch to pump.

Ted

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I can see the pump from the head when I have the hatch up - plus can hear it anyway.

It looks like it is a crimp. On the forward set up there is no movement on the set up when the bellows pump. On this aft set up there is movement, so I suspected a wire got worn at the crimp. I turned the system on and jiggled the wires and the pump ran. I took the cover off and pulled the wire and gave the wire a good tug from the crimped connector and it seemed solid. So I put it back on and tried the head, the pump would not run, tapped the wire with a screwdriver and it ran.

Next to take it off again, cut the wire and recrimp the connection. If that all works, then I will see what I can do to reduce the amount of movement.

Or the suction hose really was plugged and sitting there with a vacuum pull on it overnight freed it up.

sunchaser said:

Or the suction hose really was plugged and sitting there with a vacuum pull on it overnight freed it up.

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Nope, every time I tapped the wire and it ran the toilet flushed fine, just didn't recharge. Tapped the wire again and it recharged. So it is the wiring. Just took friggin' hours to find it!

Glad I didn't open the system up before I found the issue!!

The best advice ever given for troubleshooting is...start with the obvious, or simplest things first....especially when it is a real head scratcher.


Was just reminded of that again this morning...actually on a different thread though....

They always say 'don't let the smoke outa the wires'. But in your case could the wires have a kink that won't let the smoke flow along smoothly?

OK, back to the drawing board guys.

It wasn't a bad crimp, everything is crimped tight.

I flush, the pump doesn't run to build the pressure back up. I lightly touch the black metal chassis of the pressure switch with a screwdriver and the pump runs as normal.

Is this a grounding issue - there does not seem to be a grounding wire on there, and the set ups I see on Google images are wired just with two reds.

Arrrgggghhhh

Got it going.

Finally called Dometic. They passed me onto a young lady by the name of Heidi. I explained what was happening and what I already tried. She suggested I do two things before getting another pressure switch.

First she said, although the pressure switch settings are set at the factory and should not be touched, go ahead and use the screw on the shaft and move the shaft up and down a little bit to make sure that it wasn't stuck. She also said to put a screwdriver on the two screws at the wiring end of the chassis shafts (see below) to make sure that they were not loose and that they were making a connection.

So I did both of those things, flushed and everything worked. Cycled another half dozen time and all good. Wish I would have tried those two things one at a time to see which it was!

Now why didn't I call first!

Yeah, it's almost always a good idea to call the manufacturer first when your having an issue with a system.

In most cases they have dealt with the issue before at one time or another.

So you now have a few days of your week off to spare. What to do? You could change the duckbills ..... just for practice !

Insequent said:

So you now have a few days of your week off to spare. What to do? You could change the duckbills ..... just for practice !

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Decorating the boat for the lighted boat parade!