Bubbling Head

[sailorboy1]

My Jabsco manual head is bubbling back into the bowl after use. I’ve done the following:

- flushed water through the vent line from the outside and it seems clear
- replaced the joker valve
- flushed a good amount of acid through the system in case the hose had a blockage (it’s easy to pump and drain the bowl so it doesn’t seem to be a blockage)

Suggestions before I start taking fittings apart?

[atoll]

Originally Posted by sailorboy1

My Jabsco manual head is bubbling back into the bowl after use. I’ve done the following:

- flushed water through the vent line from the outside and it seems clear
- replaced the joker valve
- flushed a good amount of acid through the system in case the hose had a blockage (it’s easy to pump and drain the bowl so it doesn’t seem to be a blockage)

Suggestions before I start taking fittings apart?

use vegetable oil in the bowl to lubricate the pump,only use vinegar,bleach and acid damage the rubber

[sailorboy1]

How is it a pump problem? It pumps just fine.

[sck5]

This is nearly always caused by a blocked vent. Usually at the thru hull is where it happens so if by chance you took the hose off the fitting to run water through it you might have missed the problem. Could also be too much mineral buildup in the discharge line.

[ontherocks83]

To start I'd say after you fill the bowl with water, close the thru hull; then flush to the holding tank. If it doesn't bubble back then you know it's on the intake side, if it still bubbles back then you know it's on the holding tank side.

[sailorboy1]

It always pumps to the holding tank, there isn’t a y valve.

I’m blown water from the middle of vent hose both back into the tank and out the hull connection overboard.

[a64pilot]

I know you replaced the Joker, but I believe maybe you have it tweaked just a little and that distorts it just enough to hold the “lips” open.
I have to be very careful when replacing mine as any twisting force on the pipe will twist the Joker open.
Also it’s possible to distort it if you over tighten the holding screws, just a good snug is enough.
Putting silicone grease where it contacts the plastic also seems of help I figure it lets it slip and settle into a not twisted position

[peghall]

I’ve done the following:
- flushed water through the vent line from the outside and it seems clear
- replaced the joker valve
- flushed a good amount of acid through the system in case the hose had a blockage (it’s easy to pump and drain the bowl so it doesn’t seem to be a blockage)

The problem has to be a blocked tank vent...and if the vent thru-hull is the typical cap with a slit in it or a screen, there's no way you could have put enough water through the vent line from the the outside of the boat to notice.

The two most common locations for a vent blockage are the vent thru-hull and the other end of the vent line--that end of the hose and the vent fitting on the tank. Start by cleaning out the thru-hull...use a screwdriver blade, ice pick--whatever works. If that doesn't result in a spew out the vent, you'll need to relieve the pressure before removing the vent line from the tank to clean them out...so open the deck pumpout fitting VERY CAREFULLY with a hose at the ready. Be sure you're UPwind of it! Scrape out that end of the vent line and the vent fitting on the tank...reconnect the vent line to the tank
.
If there's a filter in the vent line, remove it...once a filter gets wet--which can happen when a tank is overfilled or even due to heeling--the charcoal swells and blocks the vent...one of the reasons why vent filters aren't recommended for use on most sailboats.

--Peggie

[sailorboy1]

There was a filter, but it has been taken out and replaced with a section of hose instead. Using those hose connections in the vent line allows me to connect the water hose to it and blow water down into the tank, then move the hose to the other side and blow it out the hull connection. There is no screen or cap on the outlet and water shoots right out.

[a64pilot]

Bubbling back thru to the head is when I need to change the Joker valve. That and the head draining as the head is the highest point of the system in my boat.
I have a 1” vent line to a thru hull, all run uphill and no dips, no way it’s clogging.

[peghall]

Something is preventing flushes from making it into the tank,so they're running back to the toilet. A new joker valve can keep it out of the bowl, but doesn't solve the backflow issue.

A blocked tank vent is the most common cause of backflow, but you've apparently ruled that out. An uphill run from the toilet to the tank is another possibility, especially if you're only pumping long enough to clear the bowl, which isn't nearly long enough to move the flush all the way into the tank...in which case water is doing what water always does: run downhill.

If you haven't replaced the joker valve within the last year, replace it. That will also improve the toilet's pumping efficiency. Most people don't realize that any manual toilet that's working anywhere close to factory spec can move bowl contents up to 6' in the dry mode. So try this: pump enough times in the wet mode to clear the bowl, then switch to the dry mode for at least half a dozen pumps.


Let me know if this doesn't solve the problem.

--Peggie

[thinwater]

Just to clarify...


Is waste coming back into the bowl, or are there actual gas bubbles coming with it? As others have indicated, gas bubbles are nearly always cause by a vent problem, whereas waste coming back can be either a long uphill run and/or a bad joker valve.



As others have mentioned, it is easy to get a joker valve cocked and leaking. Also, in my experience, a Raritan PHII Joker valve will fit your Jabsco head, work better, and last longer (the slit should be vertical).


Good luck. Get everything right and life will be better.

[CassidyNZ]

I have the same problem with one of the heads in my boat but it happens when pumping to the sea. My question has always been: “where does the air come from”? I’m pumping water down the system to a skin fitting that us underwater and still air bubbles back into the pan for a fair time probably 20 seconds.

I had the boat out for a clean a month or two ago and cleared all the skin fittings from underneath so I’m quietly confident that it’s not a blockage. But .. . . . . where is all that air coming from?

[crayiii]

We have the same issue with one of our electric Jabsco heads. No waste comes back, just air bubbles when we stop flushing.

The head always pumps into the holding tank then the tank has a valve to empty it overboard when allowed.

I've watched and there is no delay from flush to it going overboard.

No that I'm typing this, I'm going to try flushing with the pump out cap off and see if that stops the bubbles.

[Rapanui]

Take the replaced joker valve out and check the slits are closed at rest. If not, fit a good one. Some new ones are less than perfect.
Dry pumping intriduces air in the discharge pipe, sounds like that air is returning either via joker or via flap valve in pump head. I found scale in the pump head was causing poor sealing when I had similar problems that a new joker valve would not fix.