Jabsco Freshwater Pump Pulsating

Liberty44140

My original pump from 07 was a 3.7 gpm, 35psi Jabsco model that is now discontinued. It was an electronic on demand pump that almost acted like it had an accumulator tank, but it didn't. 

Replaced it with a 4.0 GPM, 40psi standard Jabsco FW pump. All good except it tends to pulsate, especially the shower. I realize this can stem from a leak but I cant find any leaks so I am wondering if I need to add an accumulator tank. I didnt add one initially because we really dont care about the rumbling sound of the pump, but the pulsating is something we want to do away with. 

One note - I have two filters on the inbound side of the pump. I kept the old filter because I'd need a 90 degree piece if I did away with it. I added the new filter that came with the pump because it had a finer screen. Figured two wouldnt hurt, but maybe filtering on the inbound is a problem?

Thoughts?

Aqua_Aura

I have an accumulator tank and mine seems to do the same pulsating that you are talking about.

I have a steady flow of water at the faucets but you'll here the pump change tones to a more pulsating sound. I haven't given it much thought but I'm curious if anyone has any thoughts. 

Liberty44140

It’s not the pulsating sound that I have a problem with, that I’m fine with, it’s the water flow pulsates like a hammering effect. 

rmrstlmo

Back before I knew much about these cruiser type boats with all the systems my marina replaced my fresh water pump with a larger one and I then had the pulsating issue.  I don't remember the particulars on flow rate but I complained.  When he installed the correct flow rate pump the issue went away.

LaRea

Good point.  If the flow rate is too high, the pump reaches pressure in a second or two then shuts off.  @Liberty44140 - if you run two sinks and the shower at the same time, does the pulsing stop?

Liberty44140

Good question! I’ll have to try running both the sink and shower when I’m back at the boat weds. I went ahead and ordered the larger 1 liter jabsco accumulator tank. Will report back. 

Liberty44140

Ok the answer is yes, turning on the shower while a faucet is on does stop the hammering and it’s a smooth flow. So arguably 3.7gpm was fine for the variable speed pump that regulated itself but 4.0 is too much for my system with a standard pump. Probably need 3.0 or 3.5.

however I installed the 1 liter accumulator tank and the system works great with the 4.0gpm pump. I’d rather have the larger pump with the accumulator than go to a smaller tank. So this worked out well. I removed the new filter and stuck with the old. Didn’t like the clunkyness of two filters:


 

davidbrooks

That is a nice looking setup.  One thing i did on mine when i put in a filter was i rigged up a short piece of hose so i could easily pull the filter in the fall when i was winterizing.  The other option would be to just plan on replacing the filter media every spring.  Getting the taste of the antifreeze out of the filter was a must for me.

Liberty44140

Thanks! Yea I won’t put AF in my water system. Blow it all out with air. But our cold storage never really goes below 40, and now we are in heated. 

Liberty44140

Thanks! Yea I won’t put AF in my water system. Blow it all out with air. But our cold storage never really goes below 40, and now we are in heated. 

Dream_Inn

Accumulator tank just makes so much sense.  It was one of the best updates I did on my boat.  Nice even water flow whether doing dishes or taking a shower!  At home I am on well water and have a rather large accumulator tank that works great, although you do notice when the pressure gets on the lower side (yes, I could adjust it to always stay higher, but it defeats the purpose of keeping it from cycling so often).

Liberty44140

Agree it really smoothed things out nicely 

MH342

I also added an accumulator and totally agree, it’s a great improvement. The biggest benefit we saw was when you just want a trickle of water for doing the dishes, etc …keeps the flow smooth and even.  One thing I did in my setup was add the ability to bypass the accumulator for winterization. I’ve read that the antifreeze is very unfriendly to rubber and I didnt want to risk having to replace it every few years. 

rasbury

That's a great idea...

Dream_Inn

Interesting note on the winterization.  I"ve been putting pink thru it since I've had it.  I don't put it in my tank, but I do pump it thru the accumulator.  I guess we'll see how long it lasts.

Rich_

I've had pink in mine over winter for as long as I can remember and it still functions

TonyG13

Can you install an accumulator anywhere on the main line after the pump and before the branch lines? Or does it need to be within a specific distance of the pump?

LaRea

@TonyG13 it can go anywhere in the system.  My boat doesn't have an accumulator tank, but there's so much plumbing that the water hoses act like a tank.  The hoses expand when pressurized, and I can run the galley sink for about 10 seconds before the pump comes on.

TonyG13

LaRea said:

@TonyG13 it can go anywhere in the system.  My boat doesn't have an accumulator tank, but there's so much plumbing that the water hoses act like a tank.  The hoses expand when pressurized, and I can run the galley sink for about 10 seconds before the pump comes on.

Thanks! That will make installation much easier!

Liberty44140

Yea on the winterization thing I’m not surprised on the AF deteriorating the bladder comments. Reviews for these tanks are not great from a longevity stand point. But with the jabsco quick connect fittings replacing it every few years would be super easy and a small price to pay for much smoother water delivery….. if your system benefits from it. Also could be that the rv alcohol based stuff ruins them and I’d guess that dream is only using the high test poly glycol in his system (sniff) 

LR, would Tony need to be sure to put the tank anywhere in the system, but still before his first faucet or shower? Or can he literally put it anywhere even after an output?

Dream_Inn

Liberty44140 said:

 Also could be that the rv alcohol based stuff ruins them and I’d guess that dream is only using the high test poly glycol in his system (sniff) 

Nope, I use the cheaper stuff in my water system. It ends up nice and pink too as I use the air compressor first to blow all the water out.  I only use the really good engine stuff in the motors.

LaRea

I've only used systems where the accumulator tank was next to the pump, but it shouldn't matter.  The entire plumbing system acts like a single pressure vessel.