Water pump on a 2002 Beneteau 331

[arthur.goldberg]

Hello Beneteau Owner

I recently bought a 2002 Beneteau 331. Her fresh water pump is a SHURflo 3901-0216 that's rated for 3 gallons / minute. I don't know whether it's original equipment.
We've commissioned her fresh water system. There's plenty of fresh water in the tank and the water pump runs. The antifreeze has been flushed out. But the water flow in the galley sink (and the other water outputs) is intermittent and not what I'd expect from a 3 gallons / minute pump. Please see see this video on Google photos. In addition, the water pump does not shut off when all faucets are closed.
What do you think is the problem? My guess is that the fresh water pump is broken and needs to be repaired or replaced.
If I were to replace it, what would be the right replacement model?
I've also asked West Marine this question, and will share any useful information they provide.

Thanks
Arthur

 

[kappykaplan]

Air leaks could be one of several problems. Do the faucets have aerator screens? They could have junk in them that affect water flow.

 

[jssailem]

Hi Arthur. The 331 is a very nice boat.
The water appears to be surging (spurting in the video). The water supply is a system of: Pump, pipes, connections, tank, water heater.

It appears that air is in the system mixing with the smooth flow of water (giving you the spurts). It is possible that when the winter antifreeze was introduced that a hose connection was not properly sealed. Part of the seasonal commissioning of a boat is to examine each of the systems to see if they are ready to be taken out on the water. Before I replaced the pump, I would check all of the hoses and the connections. I would affirm that all of the air has been purged from the system and replaced with water. The hot water tank is a usual suspect.

 

[Ralph Johnstone]

My vote is also air ingress in any fittings on the SUCTION side of the water pump.

 

[BigEasy]

By all means, check the aforementioned items listed by Kappy, John, & Ralph.
I have other thoughts, as I recently replaced my 15 year old freshwater pump. The rubber goods ( impeller & valves) have likely deteriorated on your 20 year old pump. If the pump motor is running, you have two options; (1) replace the rubber impeller and valve assemblies (two separate parts). (2) replace the entire pump. When I checked a couple years ago, purchasing a new impeller & valve assembly + shipping was approximately 2/3 the cost of a new pump; therefore, I purchased a new pump. I selected another Shurflo to simplify replacement. Even though the exact pump was discontinued and no longer available, the replacement pump was basically the same configuration as the old pump with regards to mounting, plumbing, and electrical connections. Simple repair that took approximately one hour. "Plug & play"; problem solved.

BTW, congratulations on the purchase of your new 331. I spent approximately 25 days (over a few years) on a 331 charter boat. Very nice boat!

 

[arf145]

As the others said, look for problems on the suction side. With an old system on another boat, I would get an air bubble trapped in the strainer that loosening and then re-tightening the screen cover seemed to fix. Of course, I can't swear that was the fix, as I was also cursing and wacking on the pump with a screwdriver!

 

[Mechone]

Does your boat have an accumulator ? Mine does and my pump was doing the same air charge was gone . Replaced accummulator

 

[BigEasy]

Does your boat have an accumulator ?

No, these Beneteau models don't have an accumulator.

 

[Ralph Johnstone]

I was also cursing and wacking on the pump with a screwdriver!

Pretty much a universal cure for most things .

I know that when I twist the rabbit ears on the top of the TV, it really helps if I curse and whack the top of the TV with a screwdriver at the same time.

 

[DougM]

Probably air getting into the system somewhere, but also check the filter screen in the pump itself which is removable. That could be restricting flow.

Because of the age of the pump, seals and impeller may have deteriorated. pieces of impeller blades my be restricting flow.

 

[GTM]

I found that I had a hair line crack in the screen filter covers that was allowing air in the line. Had to replace several of the covers.

 

[arthur.goldberg]

Thank you everyone for your replies, analyses and suggestions. I'll digest them and take action when I get to the boat this weekend.
FYI, West Marine wrote this:

Hello Arthur,
Thank you for contacting West Marine Customer Care.
I understand you are experiencing flow problems with your current ShurFlo pump. That is an obsolete pump. The replacement is the Aqua King II 3 GPM, West Marine model number 15943921.
SHURFLO AQUA KING II 3.0GPM Pumps | West Marine
We currently have stock in our west coast distribution center. There may be some stores near you that have it as well. We have a pump that is built for us by Xylem. It will do the job just as well.
WEST MARINE 3GPM Freshwater System Pump | West Marine
We have plenty in stock in both of our distribution centers. We also show 2 in your local Lodi, NY store.
To explain the issue with your current pump is simple. I believe that due to storage or chemicals that have been added, the pump gaskets have dried up and may even have cracked. This will allow air in and cause intermittent water flow.
I hope this information has been helpful. If there is anything else we can do for you please let us know. Thank you for choosing West Marine for your freshwater pump needs. Have a great boating day.
Fair Winds!

I do appreciate their effort to write an extensive and personalized reply. What do you think of their analysis and recommendation?
Regards
Arthur

 

[jssailem]

West Marine, once you get past the sales pitch... "the pump gaskets have dried up and may even have cracked. This will allow air in and cause intermittent water flow"

It is certainly a possibility. I would start simple and work towards the pump. There could be many sources of air ingress to the system. Hoses and the connections are where I would start. Certainly making sure the on spout screen is clean is in the list of usual suspects. Working your way back to the pump, you could try a gasket kit if the pump looks to be in good condition. No major corrosion, wiring all looks good. Or you could toss it and just buy a new one, if so moved. Don't toss the old one set it near a dumpster in the marina. Some boater will pick it up, take it to their boat, clean it up and put in new gaskets and give you a cheer for sharing.

 

[trippinnik]

I bought a 331 last fall and found the bilge wasn't pumping out few weeks ago, found culprit to be the jabsco pump guard. I believe there are a few others. I noticed it was cracked and prevented the suction.