Jabsco Head Wont Pump In Seawater

[LunaReve22]

Hi All!

New to the forums and new to sailboat ownership here.

My wife and I are owners of a new-to-us 1991 Hunter 28. She's in great shape sailing-wise, but as we've come to learn, there's always something that needs fixin'.

Our head won't pull in any seawater. It will flush fine when we put water in the tank and pump it out, but when we flip the switch to fill the tank, we don't get any water. Surfing the forums and youtube, I've looked for answers but have come up short on all fronts. When we use the pump to bring in water, there's no indication of pressure build up; it just pumps and pumps with no resistance. All the seacocks are open, as far as I can tell. We did replace the joker valve, which needed replacing, but that failed to be our silver bullet.

I've seen some videos that maybe our problem may lie in a clogged line, and we are endeavoring to hook up a shop vac today to try and see if there is a blockage in the plumbing.

Any guidance is much appreciated! Thank you all for taking the time!!

 

[Ralph Johnstone]

Welcome to the site. You've come to the right place for answers.
One small item to start with: boats are not cars. You may find that either Hunter or the previous owners has installed a "different" head from what is normally found depending on cost, fit or availability.

I'll take a wild guess and surmise yours is a Jabsco manual. First thing to do is to download a copy of the Jabsco manual if you haven't already done so. I see the "installation" file I have is too large to upload so I suggest you visit their site for the manual.

As you have not experienced any resistance from pumping, one possible source of trouble is with the pump check valves shown as part #21, or #19, or any other parts associated with the pumping action.

If you have a blockage in either the pump suction or discharge, you will have resistance to pumping.

My suggestion is to tear the pump down and see which part has failed and replace.

Barring an investigation of the pump is to purchase a whole Jabsco pump assembly which I believe is just about the same price as a new Jabsco head.

I know this doesn't look tooo encouraging but your only other choice is to eliminate the Jabsco and invest in a quality Raritan head which will eliminate all the problems you will encounter with the Jabsco. The Raritan is an exact replacement for the Jabsco. Footprint, piping, toilet paper, the whole schmear.

 

[Tally Ho]

You could start at the the thruhull (unclear if you know high one is for the toilet fill) and close the valve, remove the hose and crack the valve open to see if you are getting water in. If so, check the hose for blockage…I would reconnect to the valve, remove the end at the toilet, and open the valve again…water coming out of hose? If that all check out and you are getting water that far, then it must be in the pump. A rebuild kit is available for a Jabsco pump or better yet, order a new pump assembly….about the same price and you know you are starting with a working pump.

Greg

 

[Peggie Hall HeadMistress]

Hi...welcome aboard sbo.com!

Our head won't pull in any seawater. It will flush fine when we put water in the tank and pump it out, but when we flip the switch to fill the tank, we don't get any water.

What is the make/model of your toilet? If you don't know, post a photo of it taken from directly above the PUMP (all toilet bowls look alike).

When you say "put water in the "tank," are you referring to the toilet bowl? If not, where is that tank located in the system?

--Peggie
(why am I always the only one to ask questions before offering advice?)

 

[Ralph Johnstone]

(why am I always the only one to ask questions before offering advice?)

For the same reason we N E V E R ask for directions when we're out driving with the family. It's all tied up with our sense of adventure and discovery.

 

[Terry Cox]

where is that tank located in the system?

The tank on our 1989 H28 was located behind a bulkhead, stern side, in the aft cabin.

 

[Tally Ho]

For the same reason we N E V E R ask for directions when we're out driving with the family. It's all tied up with our sense of adventure and discovery.

View attachment 209198

Or why we never “RTFM”. ;-)

Greg

 

[Peggie Hall HeadMistress]

The tank on our 1989 H28 was located behind a bulkhead, stern side, in the aft cabin.

You also had a tank that you filled to flush the toilet as he's doing???? This is what he wrote: Our head won't pull in any seawater. It will flush fine when we put water in the tank and pump it out, but when we flip the switch to fill the tank, we don't get any water
WHAT tank????? It can't be the holding tank....

--Peggie

 

[Terry Cox]

You also had a tank that you filled to flush the toilet as he's doing

No. The holding tank was located behind a bulkhead in the aft cabin. the bulkhead was on the aft side of the bunk and the tank was on the aft side of that bulkhead. It was a sea water supplied manual toilet; Jabsco, I'm guessing.