Bilge pump issues

[FastOlson]

Hello All Sailors.
I’ve gotten some good advice from you before, so hope you can help me out again.

I’ve got a Beneteau Oceanis 31. The Bilge pump isn’t removing water out of the Bilge in Automatic or Manual. It tries to pump in manual switch position , the pump pulls some water, I can see water movement in the hose, but it does not drain the Bilge

I disconnected the strainer at the inlet , in the Bilge, and sucked via shop vac from there ,
I’m about to swap float switch, after that I’m out of ideas.

Am I wrong to think the Bilge pumps out the stern area. ? The boat was bottom painted in July so I’m wondering if it’s plugged up. ? Frustrating.

Painting the bottom will have no connection with internal parts like that pump.
If trouble shooting this, I would start where you did, in general. If the hose from strum box to pump is OK, then it might well be the pump. BTW, those Parr-Jabsco pumps are near indestructible --- out boat came with two of them from the factory.
Having said all that, agree with other sages here that the diaphragm and check valves should be verified. Also, and not an everyday thing, make sure that the existing hoses actually are still connected to the thru hull.
Once you get the pumping going, DO change to a dedicated thru hull for each bilge pump, if this is not the way it is now.
Our boat has three: one huge manual pump accessible from the helm, and two of those $$$ Jabsco 12 volt pumps in the main bilge. (I have helped save one sinking sailboat, and am *unanimous in my opinion that more working pumps are Better.)

* thanks to Mrs Slocum of AYBS......... !

 

[MitchM]

pull the pump body and check that any plastic fittings from the hose have no hairline cracks. i had a cracked elbow fitting on a rule 2000 that was a #$%^^ to diagnose. the apparently cracked due to normal boat vibration after 10 years, even though the pump base containing the filter was firmly attached to the bilge floor, and the pump itslf was securely held in to its by the 2 plastic tabs.

 

[Pirate Dave]

This is easy. Disconnect the hose from the pump and turn on. Is there water coming out the pump? Is so the issue is in the line. Check for kinks or bends and obstructions. If all is good, force some water into the hose until it comes out the other end. They can get airlocked.

 

[Benny17441]

My Beneteau has 2 pumps ( inadequate) that feed into a single hose. Both pumps have in fine filters. Beneteau provided my boat with a pretty good manual that shows the layout of most systems including bilge pumps..... bet there is one for yours as well.

Greg

Each pump should have its own discharge hose and port. You are probably relying on check valves to keep water from recirculating inside the bilge; these valves are prone to failure causing them to remain open. Never favored the installation of a backup to a mere convenience item. Bilge pumps are rated in a bench under no load conditions so it is quite normal that a 750 GPH pump may only deliver 150 GPH in real life depending on the installation. The regular bilge pumps are designed to remove incidental water that collects in the bilge and not for safety. A failure is a mere inconvenience as water in the bilge can always be manually scooped up so I deem backup pumps to be unnecessary and another source for problems.

 

[jlp0217]

You clearly said you cleared the line from the bilge to the pump, and yet several people mentioned screens & check valves in that line. You did not say you cleared the line overboard, you don't even know where it exits. Use your shop vac on the hose on that side of the pump. After clearing any standing water in the hose, air should flow freely, either blowing or sucking. Tape the vac to the hose, and go outside and find the through hull, probably aft near the toe rail. If air does not flow freely, snake the line with a plumbers snake.
Also check that the pump pumps water with the ouput hose disconnected ( use a section on hose back to the bilge, if the pump is not in the bilge).
In my Jeanneau, the auto bilge pump is a separate centrifugal pump connected to the float switch. If the pump is not on when the float is submerged or you lift the float, the float switch and/or the pump (if separate) is bad.

 

[NYSail]

Each pump should have its own discharge hose and port. You are probably relying on check valves to keep water from recirculating inside the bilge; these valves are prone to failure causing them to remain open. Never favored the installation of a backup to a mere convenience item. Bilge pumps are rated in a bench under no load conditions so it is quite normal that a 750 GPH pump may only deliver 150 GPH in real life depending on the installation. The regular bilge pumps are designed to remove incidental water that collects in the bilge and not for safety. A failure is a mere inconvenience as water in the bilge can always be manually scooped up so I deem backup pumps to be unnecessary and another source for problems.

Yes indeed each pump should have a separate discharge and thru Hull..... but Beneteau did not do it that way on the 423.... y fitting after both pumps into a single hose then overboard.... no check valves either. These are two centrifuge pumps so water does not flow back but just a horrible design. And pumps are small at 3.3 gallons per minute each and loud..... I have a dry bilge unless I run the ac bit it is a winter project.

Greg
Souleil

 

[NYSail]

My

Thanks.

Where are they ?

pumps are under the starboard salon setts above bilge

 

[jlp0217]

NYSail - FYI those are diaphragm pumps, not centrifugal, thus 2 check valves per pump, both resisting backflow through them, but if they are Y'ed into a single output line, it should be twice the size of each pump outlet.

 

[NYSail]

Diaphragm..... ok. But the single hose out is the same size as the hoses in. Overload. So I assume the check valve is built into the pump....

 

[Gunni]

A diaphragm pump works like your heart, the intake valve closes to allow the fluid to exit the discharge valve. Beneteau ran another power supply to the bilge for a second bilge pump, but it is not typically installed. A previous owner must have done so without enlarging the discharge hose or installing a second thru-hull. You have yet another manual bilge pump at the helm, and hopefully a dry-wall bucket for your Plan D. Don Street says you hand the bucket to whomever is freaking out to keep them occupied and too busy to moan.