Electric bilge pump runs but does not draw water (Beneteau 31)

Apr 26, 2019
10
Beneteau Oceanis 31 Toronto Islands
The bilge pump on my Beneteau 31 does not draw water. The electric pump motor seems to be working but it will not pump out the bilge. Am thinking that the pump mechanism may have failed or been damaged over the winter (on the hard). Has anyone experienced this? Solutions? Thanks.
 

Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
The bilge pump on my Beneteau 31 does not draw water. The electric pump motor seems to be working but it will not pump out the bilge. Am thinking that the pump mechanism may have failed or been damaged over the winter (on the hard). Has anyone experienced this? Solutions? Thanks.
It happens all the time with my pump if the bilge is dry. The pump loses it's prime, and will spin and spin with no pumping going on. If I fill the bilge up fairly high and turn the pump on and off a few times, it will prime itself and start pumping. Once the pumps starts working and shuts itself off, it will keep the prime and start up again with no problem. Unfortunately, this means I have to keep the bilge wet.
 
Mar 20, 2016
594
Beneteau 351 WYC Whitby
What type is it ? The traditional Beneteau one motor with rubber diaphragm and valves ,if it is take it apart see if debris has stuck the valves open or if diaphragm is ripped.
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Likely the Jabsco diaphragm bilge pump, check the simple stuff like the prefilter screen and hoses, then move on to the valves and diaphragm per Mechone.
 
Apr 26, 2019
10
Beneteau Oceanis 31 Toronto Islands
Thanks all... there is water in the bilge and water line and there does seem to be some minor movement in the water in the line but insufficient to actually drain bilge. Original Beneteau equipment. Have cleaned screen, will look into valves/diaphragm next.
 
Mar 20, 2016
594
Beneteau 351 WYC Whitby
Also my boat has a valve to switch between sucking the bilge or ice box refrigerator,if you do make sure you are in position for bilge
 
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Sep 3, 2013
38
Beneteau 331 Brewer's Warwick
Did you clean both the strainer on the intake as well as the screen before the pump? On the 331 the screen is under the sink in the head. Also make sure you have a tight seal on the screen housing after cleaning screen
 
Oct 8, 2013
33
Beneteau 321 1999 Rose Haven, MD
I had the same problem with our 321, and found two problems, both identified above: I had not set the valves in the correct position to pump from the bilge (from pumping out the icebox)...; and, my strainer had a bad seal, so the pump was just pulling air around the strainer cage. I replaced the 'pump guard' strainer (and set the valves in the correct position...) with a spare lurking in my spares locker, and voila! While you are mucking around in there, it might be a good time to clean up the float valve, if you haven't already replaced it with an electronic one. Good luck!

Adam
 
Jan 7, 2014
395
Beneteau 45F5 51551 Port Jefferson
I agree, the strainer seal is the easiest to check first. I apparently dropped the O ring into the nether worlds when I was cleaning the strainer to my shower sump. It disappeared and now I can't get a prime, a new one is on order.
 

MitchM

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Jan 20, 2005
1,011
Nauticat 321 pilothouse 32 Erie PA
sometimes people forget to winterize the fresh water and bilge pumps by running antifreeze thru it. look for a crack in the (water pump) filter housing or plastic fittings where the in and out hoses attach for the bilge pump look for a crack at the bilge pump inlet or outlet elbows or a split in the hose.. get some gorilla tape or other quick seal poly tape and hope that's the problem...
 
Jul 23, 2009
857
Beneteau 31 Oceanis Grand Lake, Oklahoma
As some people have noted, this is likely a diaphragm pump. I have not had to service mine but I have located a rebuild kit just in case. IIRC I found the parts at pumpvendor.com, I also found my cooling impeller there.