Freshwater system & pump help, please

[Streff]

I have a Whale freshwater pump that is fairly new. It is a diaphragm pump. And it has worked perfectly since installation. The pump is in the engine room & sits higher than the water tank.

A few days ago, I decided to clean the pre-pump filter/screen & added a bit of pressure to the accumulator tank. The tank pressure was at 30ish psi and the pump cutoff pressure is 45psi. So I pressurized the tank to 43psi or so. The inflator pressure digital reading does not match the older analog gauge attached to the tank but close enough.

Everything worked fine for the following 2 hours. Then I heard the pump running almost continuously with no water flow to the faucets. Turned it off and checked everything I can & all seems in order. I opened the pump body, checked the pressure switch & diaphragm … all looked good. The tank is full of water, I see no air leaks (still went ahead & tightened all clamps), the pump is getting full power.

I then attached my backup pump (which is new) and it also runs but no water flow.

Shorewater still works as normal. No issues.

I tried a dozen different maneuvers.. resetting the accumulator tank, opening the tank cap in case vents are clogged, faucets on, then off … still no water flow.

Would very much appreciate any comments or ideas.

Thank you

Streff

 

[Todd R]

Is the pre-pump filter/screen body full of water? If not, you may have an airlock. Also check to make sure the o-ring on the filter/screen body is still in place and has not been damaged. If possible, bypass this component to test if water flow is restored with it removed, if so then there is most likely an air leak in that component or one of its connectors.

 

[O C Diver]

First, verify there is water in the tank you are drawing from.

Second, verify the valve is open and all other water tank valves are closed (as you're pulling up hill to the pump).

Third, verify all valves between the tank you're drawing from and the pump are open.

Forth, verify the filter screen before the pump is clear and properly sealed.

Did you find anything in the filter when you opened it?

Ted

 

[Iggy]

Working with water can suck at times. If I could, I would try to lower the pump. since the pump is higher. I would full the tank first to the level above the pump. Not knowing your boat, not sure if that's possible? If there is an air lock, the in coming water may force the air though the pump. I know you said the tank is lower than the pump, but I can't imagine the pump is over the tank completely. Also "the tank is full", to the top? In my boat, the pump is about 6 to 8" higher than the bottom of the tank.

In other words, you would be raising the level of water to meet the pump. Making it easier for the pump to pull the water up.

Also, in testing at different connections. It will be easier to find the problem since some connection are higher than the tank.

I could be completely wrong in this, buts that my train of thought. I am thinking you have done the normal stuff by now. Valse are open, filters are clean. Good luck!

 

[SteveK]

I suspect the diaphragm has failed. However before you pulled it out again, bleed off the air pressure with a tap open and pump on.
If reduced pressure does not get it going, replace diaphragm.

 

[Delta Riverat]

I'm thinking that also. Raising the pressure of the accumulator tank may have damaged the diaphrams.

 

[Iggy]

What are the specs on pressure? At 43lbs, that almost the same as the pump. The pump may not be able to cover come that? Yes?

 

[SteveK]

What are the specs on pressure? At 43lbs, that almost the same as the pump. The pump may not be able to cover come that? Yes?

That is my thought, preset should be 2-5lbs below the pump turn on pressure.

 

[SIBERNUT]

Id be looking for a check valve once you determine the leak.

 

[Streff]

Thank you all very much for the comments and ideas. To answer so e of the question, the pump has a 45psi cut-off, the Jabsco tank has instructions written on it to pressurize to match the pump. I had set the tank 2 psi lower than the pump.
The pre-filter screen is clean, tanks are full and valves are open. There aee no air leaks that I can find on the inlet side.

Taking your ideas, I did lower the pump level by 30” which helped prime the pump easier, then I disconnected the post pump connection & put a bucket under the outlet. the pump then started moving water. When I connect the outlet hose.. the pump stops.. I then disconnected the outlet pathway after the one-way valve, put a bucket under it and the pump started moving water. After the one-way valve, it’s a straight shot to the accumulator. So it seems that the accumulator is somehow responsible..

I reset the accumulator by following the Jabsco instructions. Interestingly, now the accumulator gauge only goes up to 30psi despite putting more air in it. Once I open a faucet the pressure drops to 10psi on the gauge and stays there. So the pump does stutter a bit. Resetting the tank improved things.

I do have a new larger accumulator tank ready to be installed. I tried taking off the current tank and it’s just not budging. Not sure how to proceed but I will keep at it. Fixing yhe tank will probably help get the pump back to normal.

Thanks again

Streff

 

[SteveK]

The accumulator air pressure needs to be 2-3lbs below the pump turn on pressure, not the pump cut off pressure IMO

 

[Frosty]

I'm a little out of my depth here, but was recently re-reading some accumulator tank instructions prior to installing one. I see two things that I wonder about.

First of all, when they say 2-3psi lower than the "cut in" pressure of the pump.... what does "cut in" actually refer to in the pump specs? I mean I know that pumps will have a psi rating, but is that the "cut in" pressure?

Also, see about where they say in an existing system to take the pressure off before adjusting. Is that what you did? Just curious if one made an adjustment without doing that if it would mean the setting was inaccurate or ?

 

[O C Diver]

The accumulator air pressure needs to be 2-3lbs below the pump turn on pressure, not the pump cut off pressure IMO

I've done several of accumulator replacements, it's generally 2 PSI above the turn on pressure.

Ted

 

[Frosty]

@O C Diver said:

I've done several of accumulator replacements, it's generally 2 PSI above the turn on pressure.

Well that's interesting. Because when I was trying to figure out how to set it (helped a friend install one in an RV), I found instruction manuals from a number of different brand accumulator tanks (he had bought an Amazon model with no guidance documents at all) and they all said 2-3 pounds below "cut in pressure" of the pump. LIke the one I posted a screen shot of in my previous post. (That one happened to be from Cleghorn Waring.)

I still don't know what "cut in pressure" is and how it relates to the pressure rating of the pump though (didn't find that verbiage in the pump specs). Kind of sounds like it might be "turn on pressure" though.

 

[O C Diver]

@O C Diver said:

I've done several of accumulator replacements, it's generally 2 PSI above the turn on pressure.

Well that's interesting. Because when I was trying to figure out how to set it (helped a friend install one in an RV), I found instruction manuals from a number of different brand accumulator tanks (he had bought an Amazon model with no guidance documents at all) and they all said 2-3 pounds below "cut in pressure" of the pump. LIke the one I posted a screen shot of in my previous post. (That one happened to be from Cleghorn Waring.)

I still don't know what "cut in pressure" is and how it relates to the pressure rating of the pump though (didn't find that verbiage in the pump specs). Kind of sounds like it might be "turn on pressure" though.

It could very well be below. I tend to follow directions and remember it being 2 PSI off the pump turn on pressure.

Ted

 

[Dockmaster]

@O C Diver said:

I've done several of accumulator replacements, it's generally 2 PSI above the turn on pressure.

Well that's interesting. Because when I was trying to figure out how to set it (helped a friend install one in an RV), I found instruction manuals from a number of different brand accumulator tanks (he had bought an Amazon model with no guidance documents at all) and they all said 2-3 pounds below "cut in pressure" of the pump. LIke the one I posted a screen shot of in my previous post. (That one happened to be from Cleghorn Waring.)

I still don't know what "cut in pressure" is and how it relates to the pressure rating of the pump though (didn't find that verbiage in the pump specs). Kind of sounds like it might be "turn on pressure" though.

Cut in pressure is when the pressure drops and the pump turns ON. Cut out pressure is when the pump builds pressure and then turns OFF.