Fresh water pump pulsating - is it end of life

CougarCruiser said:
I just strayed away from the norm, and am jumping in with the Jabsco V Flo variable flow pump. I hope the quality is there on the unit, and considering I heard how loud it was in a cabinet at the boat show, I am confident in it's noise control.

Ended up ordering from the site sponsor, BOE. Great price and no tax!
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Report back with your observations after you get them installed. I sure I am not too far from new pumps with mine now at the 14 year mark.
 
Cougar,
I am looking at a new pump right now. Any first impressions of your new VFLO pump? I am considering the same one...

Thanks!
 
Actually...looks like it's a no-go for me. Apparently this pump is not ignition protected!
 
Just got off the phone with Xylem/Jabsco technical support. This pump is not ignition protected. The tech support guy says "yes, it is ignition protected, but not for gasoline applications, only diesel." I stated that means it is not ISO 8446 ignition protected at all, but he seemed intent on being ambiguous.

So, can't use this one in a gas boat bilge, unfortunately. I hope no one is, because Jabsco is not clear about this in their marketing documentation. The owner manual does state the following:

"Installation Notes: To avoid the risk of fire. Be sure that the area where pump is installed is isolated from gas, fuel tanks, electrical wiring looms or flammable substances. Failure to do so may cause injury or death."
 
bajturner said:
Cougar,
I am looking at a new pump right now. Any first impressions of your new VFLO pump? I am considering the same one...

Thanks!
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Bringing this back since I have now had a couple of trips with the new vflo pump....


Pro's:

1) The thing is dead quiet. My pump is under the galley in a forward compartment. You can barely hear it if at all unless it's running full steam.
2) Install was cake. Nothing special needed
3) Power consumption is very very minimal.

Con's

The only think I have identified is that you don't get the immediate burst of pressure in your vacuflush systems. When you are wanting to pull water in after the vacuum suction, it does take a few seconds (3-5) of water increasing to full flow. If you are a boat that just #1's, it's all liquid so not a big deal. If you are trying to get a power flush for a #2, you might not like the immediate satisfaction of a massive amount of water immediately.



All in all, I'm pleased with it for everyday use. I'll take the added couple of seconds during those rare occasions for it to build pressure for increased flow. Showers work great, faucets work great, etc... Love the fact that it's quiet.
 
"If you are trying to get a power flush for a #2, you might not like the immediate satisfaction of a massive amount of water immediately."

Add water before flush ???
 
So my problem is back. It actually never went away, I just thought it did. One of my two freshwater pumps would sometimes start pulsating. Like it was being turned on and off very rapidly. Doesn't always do this. The other pump works fine at all times. So I finally replaced the pump with a brand new one. Guess what. Same problem. So now I know the problem isn't from the pump. Then I determined it only happens when the hot water is hot. The hotter the water the more pronounced the pulsating. When the water heater is cooled down it works fine.

Two other bits of data. The accumulator is mounted right next to the HW heater and the pressure valve on the HW heater leaks. I need to replace it. The pump furthest from the accumulator is the one with the problem. I am open to any theories and ideas.
 
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Bill, since you replaced the pump and have the same issue, IMO it all boils down to a leak.

Your observation on the HWH points to expansion and contraction events that affect the possible source of the leak. Since you've stated that pressure valve on the HWH has a leak, it becomes obvious that replacing it is the step #1. Once it's done, go back to the monitoring mode and see if the problem will be solved.
 
Thanks Alex. I will do that. I am still scratching my head on why only one of the two pumps exhibits the problem, but if the new valve solves it I'll be happy.
 
A leak will obviously cause the water pump to cycle, but your description says pulsating. The accumulator can cause t hat symptom if it is full of water and has no air space inside. When you replace t he relief valve on the water heater, try draining 1/2 the water out of the accumulator while the pumps are off. When the pumps pressurize the system again, the air trapped in the accumulator will compress and that should cushion the pumps and stop the pulsating.
 
Thanks! I got the valve off and it's set at 75psi. I found a 125psi locally. I checked the tank and it's rated at 150psi. So I think I can use the 125psi since it is lower. But I'll check with a plumber.
 
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Wow. I replaced the leaking t&p valve with a 125psi and turned on the hot water heater. After a while the accumulator self destructed and water started spewing out of it at a seam, where the screwdriver is inserted. I have capped the line. The new pump I installed doesn't need an accumulator (Aqua King II) so I am going to use only that pump until I figure out what to do next.
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After three days with the accumulator removed it's clear it was never working since I owned the boat. Everything is working exactly the same as before. I took the accumulator apart and there is no bladder. It's simply two hollow plastic cones glued together. So like Frank mentioned it was probably full of water and had no air pocket left. Heck, I could probably just epoxy it back together and re-use it.

For those of you with working accumulators, how much flow do you get when you turn on a faucet before the pressure drops below the pump turn-on threshold?
 
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On my boat, with dual water pumps, I can notice very little pressure increase when the pumps cycle on. With the accumulator out of the system, the pressure drops to almost a dribble until the pumps cycle.

And, if you want to know how I figured out what happens when the accumulator is gone, just wait until you have one explode on you. I was tying up at a dock 150 miles from home and heard a huge POW!.....Very much like a shotgun blast. I opened the hatch and there was water running everywhere. While getting my wife and dogs off the boat, I had horrible visions of the boat sinking right there at the dock from every conceivable cause. The cause was very quickly evident when I got to the bulkhead and saw chards of accumulator hanging from the water line. I was relieved to find that the boat wasn't going to sink and the water flow in could be stopped by turning off the water pumps. I had spare water line and some fittings on the boat so was able to "bridge the gap where the accumulator fit. When we got home, I examined the OEM accumulator tanks but decided to upgrade to one with a bladder inside. Checking the air pressure is now just a regular part of my pre-departure check list and a bicycle pump quickly tops off the accumulator tank to 45psi.
 
Thanks Frank. Do you recommend a particular model with a bladder? Mine is at the end of a line and has just a single fitting. The marine ones I have searched for all have inline dual fittings. I guess I could put it in the same place and just cap one of the two inline fittings. Although moving it to a more accessible location would be nice.
 
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fwebster said:
On my boat, with dual water pumps, I can notice very little pressure increase when the pumps cycle on. With the accumulator out of the system, the pressure drops to almost a dribble until the pumps cycle.

And, if you want to know how I figured out what happens when the accumulator is gone, just wait until you have one explode on you. I was tying up at a dock 150 miles from home and heard a huge POW!.....Very much like a shotgun blast. I opened the hatch and there was water running everywhere. While getting my wife and dogs off the boat, I had horrible visions of the boat sinking right there at the dock from every conceivable cause. The cause was very quickly evident when I got to the bulkhead and saw chards of accumulator hanging from the water line. I was relieved to find that the boat wasn't going to sink and the water flow in could be stopped by turning off the water pumps. I had spare water line and some fittings on the boat so was able to "bridge the gap where the accumulator fit. When we got home, I examined the OEM accumulator tanks but decided to upgrade to one with a bladder inside. Checking the air pressure is now just a regular part of my pre-departure check list and a bicycle pump quickly tops off the accumulator tank to 45psi.
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That's some story, Frank. Thanks for sharing.


I never had bladders (accumulator tanks) on my boats, and don't "miss" them....LOL


It's interesting, why some models have them and some don't, and those don't have them don't feel a need? My logic tells me if the water system can work fine without it, why add an extra component to worry about (as in your worst case scenario, exploding).
 
I finally solved the mystery cycling pump problem. Turns out the new pump just needed it's shutoff pressure turned up higher. That part of the pump I replaced had failed. It was turned up to its highest setting but was turning off at a much lower pressure. Setting the pressure and why is explained in detail in the pumps manual.

One other thing I did was screw in a pressure gauge where the accumulator was. Now I can monitor the pressure in the lines. It helped me determine the proper shutoff setting by seeing what the good pump was doing. I am going to leave that installed and do without an accumulator.
 
electricaldoctor said:
Your pump will probably cycle more often without an accumulator.
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This particular pump is a Shurflo Aqua King II. It has a new bypass feature that the manual says eliminates the need for an accumulator. So far it seems very smooth. When I shut off a faucet the pump stops immediately. It does not continue for a few seconds to reach the shutoff pressure. Yet per the gauge I installed, the line is right at the shutoff pressure.
 
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