Bilge pump issues

[Suspicious Behavior]

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.

 

[Calif. Ted]

You say pump runs so the switch is not the problem, is it a remote diaphragm pump ? These work well but do have 2 rubber check valves that can become clogged or damaged requiring occasional rebuilding the pump, and a diaphragm which rarely fails but could if old enough.
ABYC requires bilge discharge to be above waterline at any angle of heel which usually ends up being high on the stern part of hull towards transom .

 

[Suspicious Behavior]

Thanks for your reply Tom . It’s a single diaphragm pump according to West Marine.
I used the shop vac to suck thru the line, then blew thru the line, from the Bilge to the pump.
Kinda last resort. No success. It seems the water is not getting thru the pump. It pulls it then I’m thinking dribbles back down even when the pump is left on for a few minutes.

Is that diaphragm easy to get to if I pull the pump ?

The fact th at the pump only works in manual and not automatic a sign the float switch is bad too ?

 

[capta]

Sounds to me as though the diaphragm has become fouled or broken. Even something as small as a few hairs will cause a problem with a diaphragm pump. Open it up and take a look. You should always have a diaphragm kit on board in case the diaphragm has failed.

 

[Calif. Ted]

The fact th at the pump only works in manual and not automatic a sign the float switch is bad too ?

Yes, if lifting the switch while in auto mode does not trigger pump.
Most common is a Jabsco and just takes a nutdriver to disassemble once removed, just remember which way pump body is oriented. I'd rebuilt mine about 8 years ago and was able to get a rebuild kit from Worst marine with a little difficulty. The most vulnerable parts are actually the rubber check valves. Rather like a heart valve they are thin and have a thin stainless frame for support. When my pump failed recently a rebuild kit was not readily available and corrosion from the stainless parts had mucked up the valve seats in the plastic pump body so I replaced with a new one.

 

[LeslieTroyer]

My guess is you want it more empty than pump can deliver then when it backflows it’s even more frustrating. Lots of pumps can only pump to 1/2-3/4” then if you don’t have a back flow preventer (good not to have) you’ll get a gallon or so back I to the bilge.
Some diaphragm pumps can get more than centrifugal pumps but at the cost of flow rates.

Les

 

[Davidasailor26]

How much water is in the bilge when you're testing it? Depending on the placement of the houses the pump might not get out the last inch or two. If the level is too low that would explain why the pump doesn't starter itself on automatic either.

 

[Calif. Ted]

FWIW most float switches turn on about 3 inches and off at 3/4 inch water depth.

 

[Suspicious Behavior]

Thanks for your time gentlemen.

When I blew it in/ out I let the Bilge get a good bit in it. I mean 3-5 gallons. It would act like it was sucking it out but not actually transfer it anywhere.

I just pulled the SPX ELECTRONIC float switch cause the pump wasn’t working at all in automatic.
It’s 9 years old. Is my thinking right on that ?

 

[Davidasailor26]

It would act like it was sucking it out but not actually transfer it anywhere.

Sounds like the pump motor itself is ok but either the diaphragm or check valves are damaged or clogged.

I just pulled the SPX ELECTRONIC float switch cause the pump wasn’t working at all in automatic.

Could be, or could be that something else went wrong with the wiring. Did it ever work in automatic? Can you test the input line to the switch and see if it has 12 volts on it?

 

[Suspicious Behavior]

Is the check valve between the Bilge and the pump ? Or the pump and the exit drain ?
I’m about to you tube the diaphragm function . Will I need to pull the whole motor or ... ?

Don’t have a meter to Check the 12 volt right now.

 

[Calif. Ted]

The valves are in the pump, just like a heart the diaphragm creates a cavity which expands and contracts. When it expands one way intake valve is open and output side closed. When it contracts intake valve closes and output opens.
Motor is mounted by 2 screws and 1 screw on the cam, once removed 4 long screws hold the 2 piece plastic pump housing together containing the rubber parts.

 

[Suspicious Behavior]

Great. So I’m at the point to take the pump off tomorrow. Is this a rebuild type of thing a shop does, I don’t have time tomorrow, or replace ASAP. .?

 

[Calif. Ted]

Rebuild consists of replacing the 3 rubber parts and reassembly, probably same price to replace as pay someone to rebuild. You can get the model number off the motor and find a service kit or get a new one which requires 2 wire splices only. The following may not be the same model but it's a very common one, search for your model. New ones come with a small screen filter that will hopefully catch some of the hair and fuzz Capta mentioned.
https://www.amazon.com/12V-Light-Du...sr=8-1&keywords=12+volt+light+duty+bilge+pump

 

[Suspicious Behavior]

Rebuild consists of replacing the 3 rubber parts and reassembly, probably same price to replace as pay someone to rebuild. You can get the model number off the motor and find a service kit or get a new one which requires 2 wire splices only. The following may not be the same model but it's a very common one, search for your model. New ones come with a small screen filter that will hopefully catch some of the hair and fuzz Capta mentioned.
https://www.amazon.com/12V-Light-Du...sr=8-1&keywords=12+volt+light+duty+bilge+pump

Thanks Ted

Yes sir. Just got one ordered from Amazon. It’ll be here tomorrow.
Got to love “ Prime” service.

 

[Benny17441]

The discharge port should be above the water line to one of the sides of the hull. The float switch has a range of motion and when the water reaches a low level it will shut the pump off. Some backflow is normal as the water already in the discharge line will flow back into the bilge when the pump turns off. Some people add a Check Valve to the discharge line to prevent backflow but these valves are prone to failure and are not recommended. If the pump is not pumping it may be damaged and not priming. Try filling up the bilge with a hose and see how the pump and float switch behaves.

 

[NYSail]

Beneteau has in line filters prior to the pump..... maybe you are clogged.

Greg

 

[Suspicious Behavior]

Beneteau has in line filters prior to the pump..... maybe you are clogged.

Greg

Really ? I’ll check that out. Would it be right before the pump ?

Another thought, the pump does pull some water, however, it doesn’t leave the boat. Water move but I bet it returns when that diaphragm opens or closes, I don’t know which.

 

[NYSail]

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

 

[Suspicious Behavior]

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

Thanks.

Where are they ?