Fresh Water System Issue

[Arthurc]

Hi All, I have a plumbing issue that is mystifying the yard so thought I'd see if anyone here had any ideas.
My boat has 2 heads below and a kitchen sink in the main galley plus a few wash downs. The problem is that the fresh water pump runs continually.... sometimes.
It seems kind of random when it does it. At first the yard thought it was either the pressure sensor or the distance from the tank to the pump but this weekend I noticed something odd.
When the pump is running continually if you turn on the kitchen sink the water slows down to a trickle then a bunch of sputtering (air) and then the pressure kicks back up and once off the pump comes to a stop. That makes me think it's not the switch or pump location. I checked and it seems this only works on the kitchen faucet.

Does anyone have any ideas on what could be going on?
Air getting into the system somehow?

Thanks!

 

[HiDHo]

I would check the suction to the pump. The pump is drawing in air some where between the pump suction and the water tank. It will run constantly because of the air, when it has a suction stream of water it can build up pressure and shut off at the pressure switch setting. Check the suction strainer for a bad gasket and other mechanical fittings in the suction line.

 

[DavidM]

I would check the suction to the pump. The pump is drawing in air some where between the pump suction and the water tank. It will run constantly because of the air, when it has a suction stream of water it can build up pressure and shut off at the pressure switch setting. Check the suction strainer for a bad gasket and other mechanical fittings in the suction line.

This is pretty basic and your description of opening the faucet and getting a slug of air out pretty well nails it. Did your yard check this first? Would be the first thing I checked before looking at pressure switch settings, etc.

David

 

[HeadMistress]

If the pump is a diaphragm pump, the diaphragm may have failed. When diaphragms become worn enough they start failing by developing a little pinhole air leak...that causes the pump to "burb" (which means the pressure switch is ok...it's turning the pump on when pressure drops, off as soon as it's back up). Over time as the pinhole gets larger, the pump runs more frequently and longer, till finally it runs continually. The cure may be a diaphragm kit, or a new pump.

All that only applies to diaphragm water pumps...if it's an impeller pump the impeller may have become so worn that the pump runs continually. Or it could be a problem with the accumulator if there is one in your system.

 

[bayview]

look for a clogged filter screen between the tank and the pump

 

[Steve]

Water level low in the tank?

 

[hmason]

First question is what kind of pump is it?

 

[kev_rm]

Some pumps will fight the accumulator if u have one. Try adusting pressure switch

 

[FF]

"I have a plumbing issue that is mystifying the yard,"

Sounds like a great time to find a better boat yard.

 

[Tom.B]

I need to revive this thread as we are having this exact issue and it is driving me NUTS!!!

We replaced the (FloJet) pump yesterday so it isnt the pressure switch. We dont see any leaks or loss of water. We arent sure if the intake side has a leak, we will check it today.

Would air on the pressure side do it? We have let it run and run. I released the air from the tank by accident. How do you put in and measure only TWO psi back into it?

Please help yall. This is driving me nuts!

 

[caltexflanc]

Did you release all of the air? Typically you want the accumulator tank to be about 2 psi below the cut in pressure of the switch. Also check the accumulator for water log. Is the pump/line primed back to the tank? Which FloJet?

 

[Tom.B]

Did you release all of the air? Typically you want the accumulator tank to be about 2 psi below the cut in pressure of the switch. Also check the accumulator for water log. Is the pump/line primed back to the tank? Which FloJet?

Thanks George!

The pump is a 4405... I just found in the pump’s manual that it say NOT to use an accumulator tank. Well... that’s interesting.

So there is a bit of a back story. What is mounted in the boat (not in an easy place to get to mind you) is a FloJet 2840 system. It is a pre-plumbed deal with a pump and accumulator tank. The PO had replaced the pump with this 4405... it is NOT the pump the system came with! Still, with this pump and accumulator, the system appeared to work normally for 2+ years.

I did a impromptu vacuum test on the line from the water tank and it appeared to pass, but I haven’t ruled it out yet. The problem is that it is intermittent. Sometimes it works and pressurizes normally, sometime it runs for many minutes.

So would the tank remaining inline but not pressurized be an issue? Would it not act like bypassing it completely? If not, how did the system work so well prior to all this?

Thanks again!

 

[Arthurc]

My issue was the pump wasn’t mounted close enough to the tanks, apologies with not updating the solution.

 

[Tom.B]

My issue was the pump wasn’t mounted close enough to the tanks, apologies with not updating the solution.

No worries... ours is in its factory position which is about 12 feet from the tank outlet. Since that didn’t change, I didn’t consider it as a possible problem... and I still don’t.

So we may have solved part of the issue by disconnecting the system and pressurizing the accumulator to 25psi. We had obviously misread the label on the tank and originally thought we needed 3 psi in the tank and not 3psi short of the cut-on pressure. However, since the pump is designed to NOT have an accumulator tank at all, the documentation does not show the cut-ON pressure anywhere (nor on the label on the pump note it). Therefore, we can only guess what the tank psi needs to be.

So with the noted 25psi now in the accumulator, the system runs a little differently. It does fully pressurize, but it takes about 45 seconds, whereas prior, it was only about 5 seconds. Could this be due to the need for MORE pressure in the accumulator? Is the presence of an accumulator detrimental to the system? If so, I can’t see how. However, we are going to let it run like it is for a little while and then, perhaps, increase the tank pressure.

I have plans to call the factory tomorrow and see if they can provide any assistance.

DAMMIT :-(

 

[psneeld]

wow..I wouldn't trust many of the suggestions so far.

They were based on incomplete info...but typical for TF.

If your system now has a pump that recommends no accumulator...try bypassing the accumulator....as it was the first thing that came to my mind anyhow because of the intermittent issue. Just because something works for awhile still doesnt make it right and some accumulators fail in different ways...so a wildcard in this application.

When troubleshooting...always get rid of wildcards then known potential problems. After that, the number of variables is manageable and troubleshooting becomes easier.

 

[Tom.B]

wow..I wouldnt trust many of the suggestions so far.

Tbey were based on incomeye info...but typical for TF.

If your system now has a pump that recommends no accumulator...try bypasding it as it was the first thing that came to my mind anyhow.

When troubleshooting...always get rid of wildcards then known potential problems. After that, tbe number of variables is manageable and troubleshooting becomes easier.

Unfortunately, that is easier said than done. But here is the issue. It used to work fine WITH the tank. So I see no reason it should not work again with one.

 

[psneeld]

Not true, if the accumulator has had some sort of failure...which ones with bladders become water bound...it could be a different story.

Why is bypassing an accumulaor hard? In many cases, it is a simple cap off, or a valve shut, or a nipple insertion...should be one of the easiest things doned on a boat with a few cheap parts at most.

 

[Tom.B]

True... the accumulator could be the issue, but I don’t know that for sure at this point.

The tank CAN be removed, but it will be a PITA to do. Look up the FloJet 2840. It is a “system” qith the pump and tank plumbed together on a steel bracket. Moreover, my boat plumbing is Pex. The pipes don’t just bend around to a new location without the right fittings and extra tubing... and since they are 15mm fittings, neither Lowe’s, Home Cheap-O, nor West Marine carries them. Finally, it is on the outboard side of the starboard motor.

So while is CAN be done, it will be a permanent change, so I am going to wait until I talk to the manufacturer to confirm it needs doing. Heck, if I am going to do all that, I could move the pump to a more accessible location...which is on a list when I add a filter system, but I’d rather make what I have work for now

 

[Lepke]

The point behind having an accumulator tank is to allow longer rest times or less runs on the pump. I can't understand why the pump manufacturer doesn't want a tank unless it's so the pumps have a shorter life and get replaced more often. With a tank all the parts get less use, valves, motor, and diaphragm (if it's a diaphragm pump).
To find the cut in pressure, you need a pressure gauge in the line anywhere after the pump. Turn on a faucet and watch the pressure on the gauge where the pump starts.

 

[Comodave]

I just read the manual on a Flojet 4405. It does say do not use an accumulator tank. It also says a tank will interfere with the internal bypass valve. Therefore I would not do any more troubleshooting until the tank is removed. The manual says not to do it, so why try to figure out how to make it work with the tank?

 

[Tom.B]

I just read the manual on a Flojet 4405. It does say do not use an accumulator tank. It also says a tank will interfere with the internal bypass valve. Therefore I would not do any more troubleshooting until the tank is removed. The manual says not to do it, so why try to figure out how to make it work with the tank?

Primarily because it has worked for years with the tank and as described above, taking it out is a big-ish job. If there is no way to make it work, I will remove it, but it makes no sense that it used to work with a tank and now it doesn’t. Just looking for the shortest distance between two points at the moment ;-)

 

[Comodave]

I understand but if you are doing something that it specifically says not to do, all your troubleshooting is not valid. Just because it worked for a time does not mean that it will always work. I would get to a base system and see whar happens.

 

[HiDHo]

I had the same problem using a new ShurFlow Revolution pump as a replacement. The instructions said no expansion tank which I thought made no sense until operation of the pump caused a staggered shut down. I remove the expansion tank and solved the errattic shut down. These new pumps are designed to simulate home water pressure, open the tap the pump starts, close the tap it stops. Any air cushion in the piping system will cause the pump to hunt and have a staggered shut down or continue to run.

 

[Tom.B]

I had the same problem using a new ShurFlow Revolution pump as a replacement. The instructions said no expansion tank which I thought made no sense until operation of the pump caused a staggered shut down. I remove the expansion tank and solved the errattic shut down. These new pumps are designed to simulate home water pressure, open the tap the pump starts, close the tap it stops. Any air cushion in the piping system will cause the pump to hunt and have a staggered shut down or continue to run.

Thank you for the thoughtful reply. I am pretty sure, now, that I will just need to bite he bullet and yank out the accumulator tank. It may also mean that the previous pump is still good. Maybe I will do an (A) (B) inline backup rig with both of them... or not.

 

[Tom.B]

Hi everyone! I wanted to provide a follow-up.

I reached out to the "factory", or at least a rep, for FloJet (Xylem). Surprisingly, this is the first time I filled out a 'Contact Us' form at a website and ACTUALLY had someone reply. Anyhoo.. Here is the text from the exchange. I hope it help future TF'ers (assuming they search for the right keywords)

**Review** We can assume, based on the below conversation, that the pump WILL work with an accumulator tank... for a while, but like a good corporate citizen, he won't (and shouldn't) go on record and estimate the life of the pump. Ours lasted AT LEAST two years before it failed. We didn't cover the subject that the accumulator tank may have caused the failed check valve. However, based on the information below, we will reduce the accumulator tank pressure this weekend to 19psi. I will get the parts and fittings to remove the tank and possibly relocate the pump to a more convenient location in the near future. Sometimes those things need staring at before you jump into a fix.

Anyway, here is the discussion:



Product Type/Model: FloJet 4405

Your Enquiry: I have just replaced what I thought was a failed 4405. The pump would run continuously and I ruled out most of the common issues. Since the previous owner left a new 4405 behind as a spare, I used it to replace the old one. The original owner had replaced a 2840 with the 4405, but left the accumulator tank in the system. I see in the directions for the 4405 that is says not to use an accumulator tank. While I understand I should remove it, the removal would be a lot of trouble and the system did work previously WITH the accumulator in place. However, the system is not working as well as it did before. So my questions are: Is leaving the tank in place hurting the pump? If not, what should I set the air pressure to in the tank? What are the symptoms of a failed accumulator tank? Can the tank stay in place with no pressure and act as if it was bypassed without physically removing it?


-------------------------------------


Tom,

The problem with your first 4405 pump would be that the Check Valve is Bad and just needs to be replace. Unable to give you an idea of what time frame your Replacement Pump will fail with an Accumulator Tank. The On Pressure for you Pump is at 22-PSI so you should put about 19-PSI air into the Tank.

-------------------------------------

Thank you David. Pardon me for replying to this email if I am not supposed to, however, I have some follow-up questions.

So will having an accumulator tank in place cause the pump to fail prematurely?

We estimated the tank pressure on the cut-on pressure for the original pump and set it at about 25 psi. Will this hurt the pump sitting pressurized for a week until we can get back to the boat to readjust the pressure?

That said, would too much pressure as noted above, cause the pump to take longer to re pressurize the system once it drops below 22psi? The system worked ok before and it took about 5 seconds, now it takes over 40. Is the tank fighting the pump?

Can I get a check valve and spare pressure switch from you?

Thanks for your time!

Tom

---------------------------

Tom,

Here are your Answers for your Questions:

So will having an accumulator tank in place cause the pump to fail prematurely? - Yes but unknown when Pump will fail.

We estimated the tank pressure on the cut-on pressure for the original pump and set it at about 25 psi. Will this hurt the pump sitting pressurized for a week until we can get back to the boat to readjust the pressure? - Not at all just when you can get back reset the Pressure.

That said, would too much pressure as noted above, cause the pump to take longer to re pressurize the system once it drops below 22psi? The system worked ok before and it took about 5 seconds, now it takes over 40. Is the tank fighting the pump? - If the Pressure is Higher than the ON Pressure of the Pump then the Tank and the Pump will be fighting each other.

 

[Comodave]

Glad you got a good level of support. It answers the question of why it would seem to work for a while and then quit. Good luck with removing the accumulator, maybe rent a small kid to crawl in there...

 

[Ex Sailor]

On the topic of accumulator, why have one and what's it's purpose ? eg.,

We have 2 heads, 2 showers, tub, galley, hot water tank etc. and the water supply is straight from the tank(s) and T's off after the pump to all of the above. Everything works just great !........

FB

 

[HiDHo]

The accumulator or expansion tanks streched out the start stop sequence on the older type pumps. The thinking was it would prolong the pump life.
Ex Sailor sometimes I miss the simplicity of our sailboat with a bronze hand water pump and kerosene lanterns. We where some what modern though, we had a manual head vs cedar bucket. Oh and cooling by forward hatch wind scoop and sun shower hung from the roller furl sheet lines.

 

[Tom.B]

Glad you got a good level of support. It answers the question of why it would seem to work for a while and then quit. Good luck with removing the accumulator, maybe rent a small kid to crawl in there...

I got a tiny wife that serves the same purpose.

 

[FF]

MY Guess would be the new pump with an internal bypass relies on output line pressure to vary the bypass.

The accumulator tank pressure may be close enough to fool the pumps system .

The concept of running electric in the pump to almost no purpose does not make sense for a boat not dockside , with unlimited electric.

A LARGE accumulator tank that can handle the cold - hot expansion from a HW heater and a std pump might make the most sense .