Fresh water pump pulsating - is it end of life

ZZ13

ZZ13

Well-Known Member
Nov 25, 2009
5,328
Lady's Island, SC
Boat Info
2001 400 Sedan Bridge
Engines
Cummins 450 Diamond
One of my two fresh water pumps pulsates for a while when it first turns on. It's more obvious when just hot water is opened. I have cleaned the screen. If I were to replace the pump what would I buy? It's a 14 year old Shurflo 2095-233-234 speced at 3.3gpm and 45psi. Shurflo has nothing that matches this part number or this exact flow rate on its product list.
 
Is it losing prime? I have Shurflos in mine as well. I opened one of them up this year and actually found it was dirty inside it beyond the screen. I cleaned it up, added a bit of Vaseline for lube, and it works like a champ now. Evidently the previous owners didnt use the boat as much as we do. Hope this helps..
 
Could also have air in the hot water heater. Try opening the top valve until a steady stream of water congress out then close then pull the hot water out hose off until u get a steady flow. Make sure the water is cold not hot. If there's pressure inside it will shoot water everywhere. I had a similar issue and that fixed it
 
Thanks. After further investigation there is a slow trip at the o-ring of the filter housing. Looks like I am sucking in air at initial turn on. I'll try lubricating the o-ring to see if that seals better.

Anyone know the answer to the replacement pump part number?
 
I have a Shurflo aqua king 3.0 as a spare. Have had it for many years, keep it in the basement accept when we go on extended trips away from the home dock, then I put it on the boat along with other spares that I only take when leaving for a while.
When I bought it, I figured it would be a good replacement for whatever the pump was in the 330, which is what I think we owned at the time I bought it.
Only one pump runs on the 400 at a time except in rare cases when we have about 3 faucets going, so I guess the "other" pump is kind of my "spare".
If one of the pumps quits, I'll use the aqua king, and it should do fine.
When trying to match up a new pump, pay attention to the amps, they operate using different draw. If your breakers are sized for 4 amp pumps you will be throwing breakers with a larger pump.
 
I verified the problem is with the pump head. Now I need to decide if I want to try to rebuild that part or just get a whole new pump.

By the way, the filter screen had never been cleaned by any of the previous owners in 12 years. It was packed with plastic shavings from the hole cutouts made to the tank.

Thanks for everyone's help.
 
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Parts are readily available from PaulBparts.com.:smt024
I had a pump failure, replaced it with a newer version, that has since failed, and after replacing pressure switch and diaphram kit have reinstalled original pump.
 
ZZ13 - I finally found my data:

Use this pump: Shurflo 4148-153-E75 (Improved Model Replacement for 2095-233-234)

Shurflo Tech Support 1-800-854-3218
 
Thanks Carter. That's an increase from 3.3gpm to 4.0gpm and from 45psi to 55psi. The fresh water fittings on board are rated to 250psi. So no issues there.
 
After mine quit, I replaced it with this one (Flow Rate: 5.0 GPM, 55 PSI Max):

http://www.defender.com/product.jsp?path=-1|51|2234226|2234231&id=2127569

My old one was also 5 GPM.

The new pumps use new technology and you'll hear the difference. Instead of constantly running, the motor kicks in only when the pressure drops. So, the basic operation in in "pulsing mode". I can see the benefits in the power usage, but the new pump is also LOUD. So, when you need to use water during quite hours, you feel like the alarm clock buzzer just went off.......BZZZZ........BZZZZZ......BZZZZZ......BZZZZZZ

I wonder if anyone found a better replacement replacement for this pump (probably different brand) and/or have a silencer?
 
Alex - my dockmate had that pump installed, and the buzzing noise was the output line vibrating from the pump's higher pressure/pulses. The mechanic tied his line down in a few sopts close to the pump with some tie wraps and that cured a lot of the noise...
 
Thanks for the tip, Carter. I'll give it another look. I hope mine will be fixed just as easy.
 
Just a quick update on the noisy pump:

On my boat (and I guess that would apply to all 420/44DBs and I'm sure few other models) SR used hoses instead of plastic tubes. The hoses are held in place by clamps with robber covering. This makes the hoses pretty much "noise free". So, I had verified that the primary noise is coming from the pump itself, at least in my application.

I'll be definitely looking at a solution to either get a new (much quieter) pump, fabricate some sort of silencer cover for existing pump, or move the pump to ER.

This brings me to the question, does anyone have any recommendations on the much quieter pump, which is equivalent to "SHURFLO Aqua King II Supreme 5.0 Fresh Water Pump"?
 
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I used the pumps from West Marine, West Marine branded, and they seem pretty quiet. I have 2 pumps in parallel with a small pressurized holding tank so my pump only comes on when the pressure drops after the pressure tank has dropped so they don't continuously run. Verify the rubber mounts on the pump are in good condition and that the pump is able to 'vibrate' on the mounts and that the hard plastic mount is not touch the wall. This typically translates into vibration noise that is amplified throughout the boat. Apart from that, it is truly is just the pump, I think the WM pumps are fairly quiet but then again, I don't know how much noise yours make either.
 
Great points, Tom.

I don't remember if the new pump came with new robber mounts or did I re-used my olde ones (which were never an issue with the old pump). I also don't recall 100%, but don't think there were any plastic inserts in the robber mounts. But this is something I'll double check next time.

Update: just by looking at the manufacturer pic I see the robber mounts attached to the pump.

I was also thinking to get extra soft robber pads, which might help. I think most people don't have the issue with so much noise b/c they installed a bit smaller pump (3 or 4 GPH). This one is 5GPH 55PSI, which was replacement for my original 5.

It is kind of odd that we have a total performance mismatch. SR installed Jabsco reducer for the shore inlet, which is 35PSI and 5GPH on the onoard pump. We feel the difference big time (especially when multiple people using the water at the same time) between using onboard water via FW tank vs. city water.
 
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I never use the shore connection for FW. I just refill and use the onboard pump as most do down here, at least at our marina. Since I have 2 pumps at 4GPM (per hour would be pretty slow :grin:) I have flow at almost 8GPM and 55 psi. It is a real nice system along with the pressure tank.

If you are saying the dockside water is regulated to 35PSI, then someone replaced that with what I assume the wrong regulator. Mine is 50PSI I think although we don't use it I had to replace it a month ago because it was leaking.

Reasons we only use fresh water tank on board:
1) You can easily determine if you have a leak. If no one is using water and water pump cycles, guess what? You have a leak. You don't know where but you have one. This is how I found my water pressure regulator has a slow leak. My pumps kept cycling and it took me 2hours to find the leak, but I found it and now it is gone.
2) Boat won't sink if I burst a line. I hold 70 gallons of water and the only thing that will happen is I will transfer that 70 gallons someplace else. Water will not continuously run and flood the boat. These pumps will also not burn out if run dry, not that type of pump.
3) I am continuously cycling water thru the water tank and it is clean. We have an ice maker and use ice for drinks and it is clean water for ice and anything else you want. We only use it to gray water and ice but if we had to, you could drink it no problems.
 
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