Fresh Water Pump Problem

[Jmreim]

I have a JABSCO VFlo 5.0. Model 42755-0092 freshwater pump - it seems to supply plenty of water to all locations with good pressure. Recently, however, I’ve noticed that when all faucets are off, the pump seems to re-pressurize for about 1 second every 5 seconds. I heard this happen yesterday for the 1st time but it seems pretty consistent now. I’ve checked everywhere for water leaks but could find none. It almost seems like this is an air leak in the pump itself? Any ideas?
Thx -
Jim

 

[Scottwb96]

check your toilets... I had that happen once. Just BARELY open, but would draw the water super slow and kick the pump on every so often... Drove me nuts trying to figure out what was happening!!! good luck!!!

 

[menzies]

Nothing in a bilge?

 

[Jmreim]

dry bilge but the suggestion above to take a harder look at the toilet is probably worth pursuing. thx

 

[Giggitoni]

Leaks can be very elusive. Every time I begin to convince myself that a back flow preventer in my pressure side of the fresh-water system has failed, I finally find “the leak”. It would be convenient if all leaks were noisy and sprayed water everywhere. Usually I find them quiet and dripping slowly behind a bulkhead or in the lazarette or some other insignificant place. My latest leak was found in a small copper line which provides water to my front window washers. I’ve never used them in over 12 years!

Of course, it could be from a failed back-flow preventer....

Edit: if you have an accumulator tank, check the published air pressure in the tank.

 

[caltexflanc]

Does that pump have a separate or built-in pressure switch? Some times you have to play around with the cut-in pressure on the switch and pressure in the accumulator tank, which should be a couple psi below the cut-in pressure. Occasionally, the switches can start slowly going bad.

Off topic a bit, I found it very handy to have an in-line water pressure gauge in our freshwater plumbing system. Helped diagnose and adjust settings for the aforementioned issues, among other things.

 

[tiltrider1]

Take a pair of needle nose vice grips and clamp the hose about a foot past the pump. If it still cycles then you know it’s the pump. If it stops cycling you know you have a leak.

 

[mcboatface]

I have a JABSCO VFlo 5.0. Model 42755-0092 freshwater pump - it seems to supply plenty of water to all locations with good pressure. Recently, however, I’ve noticed that when all faucets are off, the pump seems to re-pressurize for about 1 second every 5 seconds. I heard this happen yesterday for the 1st time but it seems pretty consistent now. I’ve checked everywhere for water leaks but could find none. It almost seems like this is an air leak in the pump itself? Any ideas?

Thx -

Jim

I have the same pump. It now runs slowly when no water is being called for then shuts off due to thinking pressure is off. No leaks. Just a bad brain. Have to shut off breaker for a bit to get it working again. Naturally this started at 2 am while offshore. This is a very, very common problem with the Vflo pumps. Do a search online. Basically, they are garbage.

About to go with a different pump and a small accumulator tank. I will never install a Vflo again.

 

[sailormike]

All of the above suggestions are great! When we got our trawler back in the late 90s it had that old grey poly butalyn pipe in it and it was a royal pain in the beep. Not knowing about pex yet we ripped it all out and use those long washer supply hoses. After about 10 years they began to fail and they weren't designed to flow the volume of pex. I have now re-plumbed the boat totally using pex. I also added plenty of ball valves in the system to I can isolate in case of a leak or during cold spells and for testing purposes. also I added several Pressure gauges so that I can monitor for leak down, leaks and other problems.

 

[Lou_tribal]

Mine was doing the same, I found out after many search that I had a tiny leak from under my water heater. The leak was out of sight and water was also going out of sight, I found it by luck!

L

 

[Jmreim]

Confirmed it's an air leak in my 9 yr. old pump (Jabsco VFlo 5.0. Model 42755-0092).
Anyone have a favorite freshwater pump manufacturer/model? Demands on our boat are a galley sink, 1 wet head, a Raritan Elegance freshwater toilet and a very rarely used cockpit hose. Looking for reliability here.
Thx -
Jim

 

[Shrew]

I just got rid of that same exact model. I hated it from Day-1. Here's a parallel discussion on our sister site about problems with that line of pumps:

https://www.cruisersforum.com/forums/f115/jabsco-vflo-5-0-a-237648.html

Mine would not fully pressurize and run very, very, very slowly for hours until it overheated. It would require that I turn it off for up to 5 min. with the breaker then turn it on to get it to work.

It would 'negotiate' volume with my shower and keep slowing down more and more over the duration of the shower until both mixing valves were wide open.

It would re-pressurize periodically like I had a small water leak (that was never found). This was the last straw when it was doing this every 15 minutes. I had to turn the breaker off at night or every 15 min. I'd hear it go off for 1-2 seconds.

 

[Jmreim]

I've been in touch with Jabsco Tech Support and explained my problem. Given their response below, I surely don’t want the same pump as a replacement:

"The problems you're having are known failures for this pump and we have figured out the cause and the fix but due to the Covid Crises we have not been able make the changes to this pump, and it looks like our Plant will not be opening up until late this year."

 

[Giggitoni]

Confirmed it's an air leak in my 9 yr. old pump (Jabsco VFlo 5.0. Model 42755-0092).
Anyone have a favorite freshwater pump manufacturer/model? Demands on our boat are a galley sink, 1 wet head, a Raritan Elegance freshwater toilet and a very rarely used cockpit hose. Looking for reliability here.
Thx -
Jim

I have a Jabsco Par-Max 4, model 31620-0092. Been with me for about 10 years. We probably just sent it a curse!

 

[Turtle Blues]

Suggest dropping to a smaller pump with a lesser pressure. 40 psi is plenty of pressure for your boat. The max 4 suggested above is sufficient.

The failure issue is usually a combination of the variable speed and the 60 psi setting against a slow leak or dripping faucet or just pressure bleed loss inside the diaphragm. It triggers constant cycling.

 

[Jmreim]

Looking at the Shurflo pumps which are not variable speed and I have no accumulator tank.
Will certainly drop to 4gpm but do you think I can drop to 3gpm???

 

[Turtle Blues]

Shower heads and faucets have a 2.5 gpm restrictor orifice so there is a little buffer if something else is turned on while showering. If you do not have large demand fixtures: washing machine or fresh water heads you probably will never notice. I think you can get a larger delivery volume pump with the same lower 40 psi pressure head if you want over the 3.5 gpm rating. We are twin head and galley on the Max 4 without an accumulator (which would provide a larger buffer) and it has been sufficient.

 

[DDW]

You might want to try the Marco pump. It is also variable speed, but is a gear pump and made of metal (brass and bronze), not plastic. People have usually seen a Marco pump, that is what Reverso uses for most of their systems. Being a gear pump, there is no pulsation at all and is quieter.

It does have a couple of downsides: the reaction to turning on a faucet has a slight delay, not an issue for most things but it can be annoying if you have a shower nozzle with a trigger. Also it is not self priming, if the pump is above the tank and run out of water, you must open a bleed screw for a few seconds to get it to re-prime. I've had a few of the Jabsco VFlo pumps, great while they work but they seem eventually to fail.

The Marco comes in various sizes, the UP3 is plenty big enough for a <50' boat.

 

[RCook]

Looking at the Shurflo pumps which are not variable speed and I have no accumulator tank.
Will certainly drop to 4gpm but do you think I can drop to 3gpm???

I had an older Shurflo variable speed pump that would pump for a little while, then slow down, and sometimes completely stop, then after a while mysteriously start again. This older model was well known for problems. And it ran to an old accumulator which I suspect may have gone bad.

Removed the accumulator, as I came to understand from this forum that VS pumps may work better without one. This helped somewhat, but the old pump was still working poorly.

Replaced the pump with the redesigned variable speed Shurflo Aqua King II. It's been working like a charm, daily for almost six months now. Mine is the 5gpm model, but there are 4, 3, and 2gpm models too. 4gpm is $190 at Defender, or $172 if you're signed up on Defender First.

 

[Jmreim]

Yes - the Aqua King II is what I settled on (model 4148-153-E75 @ 4gpm) . But this pump is not variable speed - according to Shurflo, they don't make any variable speed pumps anymore. This is still the pump choice. Thx for the suggestion.
Jim

 

[FF]

The Sureflo bait well or deck wash pump has much larger motor so is stressed less.

A house adjustable (Square D) pressure regulator works great long term .

The a 2 to 20 gallon accumulator , if you can fit it , will lower the number of times the pump cycles.

If rebuilding, 5/8 copper tubing for the system delivers lots of water at low pressure , flaired tubing (no soldering) can be recreated/replaced at sea.

 

[dbltime]

check your anchor washdown (if thats fresh water), cockpit shower, engine room spigot

 

[Martin J]

Gave up with variable speed pumps and electronic switches. I know have a regular pump , disconnected the switch. Installed a accumalator and a mechanical pressure switch, https://www.amazon.com/gp/product/B07Q6WBNCV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
And a pressure gauge , No problem since

 

[richardschmidt2759]

water pump

If you are SURE you have no leaks in the system, you could have a internal leak in the pump, make sure you are not just filling up your hot water tank.all air out !

 

[Puffin_NT32]

Another source of a small leak could be the pressure relief valve on a hot water tank. My HW tank has a tendency to drip some water when heated from shore power, but we're not drawing water for a while (a higher heat level than engine coolant?). The relief valve has a vinyl hose attached going into the bilge. That drip could cause a pump "burble" (usually at 2 AM).

On pumps, I've had it with Jabsco pumps. My original Jabsco Sensor Max 17 #31755 was constantly cycling and eventually started leaking after 14 years. OK, not a bad life cycle. Pump no longer made and the Jabsco replacement is the Paramax series. I installed a Jabsco Paramax 5 GPM 60 PSI, and it was constantly cycling and surging unless all faucets were opened. Too much pressure? Stepped down to a Paramax 3.5 GPM, 40 PSI. Same problem, surging and cycling. I've got a Shurflo Aqua King #4128, 2 GPM 30 PSI. My Shurflo ProBlaster washdown pump has been working fine. Will replace the Jabsco with a Shurflo.

 

[Steve91T]

When we bought our boat it had a new Jabsco 5 gpm pump. It worked great until it started overheating. I found that it wouldn’t completely shut off. It would run at a very low rpm until it would overheat. Had to turn the breaker off and let it cool down. Finally it died. Bought a new one. It was actually quieter and worked well for a short time until it started doing the same thing. Replaced it under warranty. New one was noticeable louder and would do the same low rpm/overheat thing right out of the box.

As someone said, it seems to be a known problem. Not sure what I’m going to do about it yet.

 

[JohnEasley]

Take a pair of needle nose vice grips and clamp the hose about a foot past the pump. If it still cycles then you know it’s the pump. If it stops cycling you know you have a leak.

Great diagnostic tip. Start at the beginning, rule that out, and step through the system.

 

[Puffin_NT32]

Pulled the Jabsco Paramax 3.5 GPM and replaced it with a Shurflo Aqua King 2 GPM, 30 PSI. Pump feeds head sink and shower, galley sink, HW tank, Jabsco Quiet Flush macerator toilet, and cockpit shower. Part of my problem is that the Jabsco pumps seemed to produce too much pressure in my setup. The Shurflo 2 GPM, 30 PSI is working fine at all faucets. I have Pex water pipes, and when we hit the water switch for the toilet, I would hear the Pex banging from the pressure. With reduced pressure of the Shurflo, no banging pipes. Shurflo has pumps ranging in size from 2 GPM to 5 GPM, and PSIs up to 55. Shurflo pumps are also super quiet.

 

[Steve91T]

Pulled the Jabsco Paramax 3.5 GPM and replaced it with a Shurflo Aqua King 2 GPM, 30 PSI. Pump feeds head sink and shower, galley sink, HW tank, Jabsco Quiet Flush macerator toilet, and cockpit shower. Part of my problem is that the Jabsco pumps seemed to produce too much pressure in my setup. The Shurflo 2 GPM, 30 PSI is working fine at all faucets. I have Pex water pipes, and when we hit the water switch for the toilet, I would hear the Pex banging from the pressure. With reduced pressure of the Shurflo, no banging pipes. Shurflo has pumps ranging in size from 2 GPM to 5 GPM, and PSIs up to 55. Shurflo pumps are also super quiet.

I’m switching to this one. My Jabsco is so loud you can hear it from outside the boat. I’ll try the smaller one as well

 

[Bacchus]

If you are SURE you have no leaks in the system, you could have a internal leak in the pump, make sure you are not just filling up your hot water tank.all air out !

OK to eliminate all air in WH If you have an accumulator. With no accumulator or air in WH tank more likelihood that you will over pressurize and leak out of the OTP relief valve. If / when you use a lot of hot water and WH heats from cold to hot you get expansion and P increases. Worth keeping an eye on.