water pump runs way too long

[slapface]

Hello Fellow Beneteau Owners!

I am new to the club with the recent purchase of a '99 Oceanis 381!
Love the boat and love being on the water up here in the NW.

My problem is with the water pump for the faucets. It worked fine for the first 2 months I owned the boat, but now has problems.

Here is what happens:
I switch the pump on and it tries to pressurize the blue pressure chamber (name?), but it takes forever, and the pumps runs and runs and runs and then finally turns off. Then, you use the faucet a few times and it starts running again for what feels like forever.

So, is it the pump, the tank, the pressure in the tank, a problem with the lines?

Any help would be greatly appreciated!

 

[justsomeguy]

Is there a check valve between the pump and the blue tank (accumulator)?

 

[Ron20324]

The blue pressure chamber should be an "accumulator", designed to shorten the running time of the pump. Yes, there is a check valve in the output fitting of the water tank on my B323. It is a small plastic plunger, and a spring about the size of what you'd find in a ballpoint pen. I took them out and everything runs properly. I guess the check valve is more funtional when the tank has lower contents, thus less pressure on the line.

Otherwise, the pressure switch on the pump could be bad or just need adjustment.

 

[justsomeguy]

The blue pressure chamber should be an "accumulator", designed to shorten the running time of the pump. Yes, there is a check valve in the output fitting of the water tank on my B323. It is a small plastic plunger, and a spring about the size of what you'd find in a ballpoint pen. I took them out and everything runs properly. I guess the check valve is more funtional when the tank has lower contents, thus less pressure on the line.

Otherwise, the pressure switch on the pump could be bad or just need adjustment.

The accumulator should have a bladder of air inside, or about 1/4 to 1/3 of the tank's volume made up of air, to allow for compression. You can't pressurize a full tank of water very well!
If, when the pump shuts down and stays shut down when you don't use the faucet, then it's likely that your accumulator has lost it's air reserve, and the check valve's okay.
Is there a schrader valve on the tank?

 

[Paul Mermelstein]

You might also have some air in the lines. Is there a difference if you use only the cold, or only the hot? If you run all of your fresh water faucets, showers, etc. for a few minutes, and then try again, does that help?

Another thought, maybe the pump is starting to go bad and is not presuurizing very well.

 

[Kmarine]

Hi Slapface (love the name!)

Agree, you have to check the accumulator, we always had this issue with the new Beneteau's on delivery. If after the pump has finished pumping it then stays off then your accumulator bladder should be fine, just pop on a pump and put a little bit more air at the rear - check on the manual for the right pressure (sorry forgotten what i used to pump them to). This should also help when you open the tap and run the water, it will take longer for the pump to kick in.

failing this there may be an issue with the pump head side of the water pump before the accumulator, BUT, would only start looking here after you have checked the air pressure - normally they will run for years before issues here...

 

[justsomeguy]

Pressurize your accumulator to a few pounds below the pump's cut-in pressure.
I think.

 

[Ron20324]

And there is probably a filter right before the pump? Clogged or clean?

 

[slapface]

And there is probably a filter right before the pump? Clogged or clean?

Thanks for the help...
Yes a filter before the pump.... I cleaned that.
Yes a schrader valve is on the tank. I will start there and pump it up a bit, then let things run a bit to let out the air, and see if that solves it.

I was hoping to not go straight to replacing the pump to find that it was not the problem.

thanks again!

 

[Joe2954]

I put a 1 gallon accumlator on my 343. It boosted the pressure available to the head etc, but it seemd to run the pump forever once it kicked on. I found it less unnerving to remove the tank and go back to "on-demand". Pump runs when you run water, shuts off a couple seconds after you shut off the water.
Pull the pump chamber off the pump and clean all the valves in the diaphragm and discharge side. Pressure switch on some is adjustable.
Put a little vaseline on the seal of the filter housing.

 

[marian]

Fixing water leaks from fresh water system this spring, i removed the accumulator, to my surprise looking inside, the diaphragm was broken. Replace with new 2 gallon accumulato, set pressure 2 psi below water pump start pressure, as per accumulator manual, works great, i hope this helps.