Water Pump Died!

ScottG · October 2023

The water pump in my 2015 T@B has worked fine for nine seasons. I last used it about three weeks ago. While winterizing a few days ago I flipped on the pump while the system was depressurized, and... nothing. No whirr, girgle, hum, crunch, or sound of any kind. However, there was an obvious current draw on the battery so it was trying to do something. This likely rules out a power supply or pressure switch issue, and suggests a seized motor, but it seems odd it would quit just like that with no warning. (Maybe. There's at least one old discussion here when somebody described a similar abrupt failure.) The pump is currently on my workbench awaiting an autopsy.

So, I'm asking...

...has anyone experienced a similar failure with their pump? If so, did you figure out a resolution short of replacing the pump?
...if I do end up replacing the pump (which seems likely), any recommendation for a good alternative?

Thanks in advance for any advice or insights.

DukeHewett · November 2023

Yep, same year T@B and pump failed with no warning within the last year. Might have been the pressure switch, but it wasn't worth the time trying to troubleshoot further. We just bought a replacement that was easy to accomplish. I may have had to mover the new one over or down just a tad, but it fit fine. Not sure where we got it, but you can Google: Pentair Shurflo 4008 RV Revolution By-Pass Pump. It has worked great and supposedly will not burn up if you run it dry. Under $70 on Amazon. Good Luck and "let it flow".

jimcenname · November 2023

I live in a 2019 400, I use the pump and tank water exclusively. I've replaced pumps 3 times until I installed a Shurflo accumulator. Smoother operation and longer lasting service.

pthomas745 · November 2023

@jimcenname you certainly get some use from your trailer! Your thread about a faulty Auto Air Bleed valve helped a FB user today. That strategic whack with a screwdriver handle got them through a cold night!

otr_320 · November 2023

Our '23 320 and two prior RV's came OEM with the Shurflo Pentair 4008. No failures or problems of any kind.

ScottG · November 2023

@DukeHewett, @jimcenname, and @otr_320, thanks for the input. I'll check out the Shurflo Pentair 4008, and possibly an accumulator.

I guess I can't complain too much. I gotten nine full seasons out of the pump (though certainly not full time), and at least it had the decency to die after my last trip of 2023! :-)

DukeHewett · November 2023

Per Pentair/Shurflo regarding an accumulator:

The Shurflo will adjust the outgoing pressure and flow to match the needs of your plumbing system. This means that you do not need an accumulator tank since the Smart sensor pumps will speed-up and slow-down as required to meet the demand for water.

ScottG · November 2023

I've been looking at the Pentair/Shurflo Revolution Pumps. For 12VDC applications it appears there is a 3GPM/7.5A/55PSI shutoff model 4008-101-E65, and a 2.3GPM/5A/50PSI shutoff model 4028-100-E54.

The smaller version seems like the better choice both for water and power conservation, as well as keeping system pressure within spec. Do others concur?

otr_320 · November 2023

For what it's worth, the 4008 has a small Allen screw that adjusts the shut-off water pressure up and down.

BrianZ · November 2023

@ScottG what about the control switch unit used to turn the pump on & off? Is it working normally & does it supply the appropriate amperage for the pump? On our 2018, I rewired our SeaLevel and Shurflo pump circuits (on the same converter circuit), adding an extra fuse & relay switch, so each could use its own fuse to limit current to the manufacturer's required amperage.

ScottG · November 2023

@BrianZ, good thought, but yes the control switch is fine. After removing the pump, I checked the cut leads with a voltmeter and was getting the expected voltage when the switch was on (and nothing when it was off).

I've considered it could be a problem with the pump's internal pressure switch, but the current draw--which comparable to when the pump is running--makes me think stuck motor.

ScottG · November 2023

@otr_320, thanks. I noticed that after I dug a little deeper in to the specs. Good feature.

ScottG · December 2023

For those interested in such things, I finally dug a little deeper into the cause of my water pump failure. A proper autopsy revealed it was indeed a stuck motor. However, the problem was not the motor itself, but rather two failed bearings on the motor shaft.

The photo below shows the relevant parts of the pump (in my case an Artis Power Drive Series One). Water in the pump chamber is separated from the motor and associated mechanicals by a thick diaphragm. My best guess is that the diaphragm developed a small leak, water seeped into the bearings, and--after sitting for a few weeks--the bearings corroded and froze. Although the motor was trying to turn (hence the voltage drop when it was switch on) the shaft was held tight by the two failed bearings.

Although the diaphragm seems the most likely point of failure for pumps of this design, I'm still impressed I got nine trouble-free seasons out of it.

Image: https://us.v-cdn.net/5021717/uploads/editor/km/dr2hdq9owq6j.jpg

vhollow · December 2023

Thank you, Scott, for the final diagnosis. It is helpful to see how the pump works, and a way in which it may fail.

ScottG · May 2

To follow up on this, I really wanted to try the smaller of the two Shurflo Revolution pumps mentioned above, but was surprised to find the smaller 4028 model was quite a bit more expensive than the larger 4008 model. Regardless, I located a "Used-Like New" 4028 for a bargain and took the chance.

I installed it recently and it works great. Really great. Soooo much smoother, quieter, and consistent than the OEM pump. Although I don't completely understand how it works, I attribute at least some of this to the bypass feature of the Shurflo pumps. Now I wish my old pump had crapped out years ago! :-)

AnOldUR · May 2

Thanks to @ScottG I just made an impulse buy of the smaller 4028 model. My pump is still working but has gotten progressively louder. After a trip last year, the pump switch got bumped on with an empty water tank and unknowingly ran dry for a long time. I've had an accumulator in my Amazon cart, but I'm now hoping that swapping out the pump will help the noise problem.

Also went for a "used - very good" option for almost half price. Fingers crossed.

ScottG · May 2

@AnOldUR, I read somewhere in the pump literature that the bypass function is supposed to eliminate the need for an accumulator. One of the big differences I've noticed is that once the lines are primed, the pump shuts off immediately when the tap is closed. My OEM pump would always rattle on for a second or two to reestablish system pressure.

I think newer T@Bs are now coming with these Shurflo Revolution pumps, but I'm not sure when they made the switch.

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