Problems with fresh water pump

[Two Buoys]

While on the hook over the weekend, we noticed that our fresh water trickled out of the faucets, then some pressure for a few seconds then trickle again.

I called a service tech and he suggested trying to replace the bellow head on the fresh water pump (the motor was working fine).

After replacing the pump head, the pressure was a better but air keeps sputtering out of the faucets when running water. I also noticed that when all taps are off, the pump still hums softly and vibrates.

I checked for leaks at the manifold - it was dry. I then started looking for the accumulator bottle to check for leaks and could not find it anywhere.

Is the pump supposed to be completely silent when all taps are off?
Does anyone know if I should have an accumulator bottle, if so where is it?
What else could be causing my problems?

FYI: No issues when connected to marina water supply.

Sorry, I updated my profile to include a signature in the middle of writing this post. It didn't get included on this one.

2005 390DA

 

[J Levine]

You need to give us the year and model to give you some guidance on this one. Different models have different systems.

 

[Two Buoys]

Sorry, fixed signature.

2005 390 DA

 

[fwebster]

It sounds to me like you just have air trapped in the system. Since air is compressible, the pump may not be reaching the cut off pressure and just keeps running.

Try opening each faucet beginning with the one furthest from the pump and letting it run 30 seconds. Then do it again. You should be able to get a burst of air out of the line where it is trapped. If you do, then open that faucet and let it run until all the air is purged.

This happens to my boat every time we forget and run the tank completely dry. We have 2 pumps and purging the air from the system is a royal PITA.

After you get the above problem fixed, one thing that may help in the future is to add some air to the accumulator with a bicycle pump........turn the pump breaker off and open a faucet and let the pressure drop to zero, close the faucet, then pump the accumulator up to about 20 psi.

 

[Two Buoys]

Frank,

I ran all the taps for a few minutes each. Some air still sputters out.

I can't find the accumulator. Do I need to get to it to add the air with a pump?

Peter

 

[Steve36]

Dont you just love these water problems?
I had the exact same problem last year, it turns out we found that the hose leading from the water tank to the pump was kinked.
Since you have had the boat for awhile and I assume this just started happening than this could be a long shot.
Another think to check is the strainer on your fresh water pump. Make sure its nice and clear.
Good Luck

 

[Two Buoys]

Thanks Steve.

Strainer on inlet of pump was removed. cleaned and put back.

On a side note, I have posted to your water thread.

Peter

 

[Two Buoys]

Problem solved. The fitting on the water tank that leads to the pump intake was cracked. So, the pump was sucking air and water.

Replaced fitting and all is well again.

Thanks to all.

 

[gerryb]

I'm wondering if using one of those air pressurization winterization fittings at the dockside water inlet and pumping the system full of air would help in troubleshooting these kinds of problems? I haven't had the problem myself, but see it posted many times and it seems that actually FINDING the source of the leak is always a problem. If the system was charged with high pressure air, would you not then be able to hear the leak, even if it was a small fracture? How much pressure is in the system under 'normal' operating state?

 

[boatmailster]

I'm wondering if using one of those air pressurization winterization fittings at the dockside water inlet and pumping the system full of air would help in troubleshooting these kinds of problems? I haven't had the problem myself, but see it posted many times and it seems that actually FINDING the source of the leak is always a problem. If the system was charged with high pressure air, would you not then be able to hear the leak, even if it was a small fracture? How much pressure is in the system under 'normal' operating state?

you can't pressurize that system too much
most of connectors have o-rings as seals and pressure will "blow" them out
you can use food coloring and look for leaks that way but it won't work when pump "sucks" air and there is not obvious water leaks