Help Troubleshooting Pentair WhisperFlo Priming Issue (just replaced motor bearings)

Underwood

New member
Aug 8, 2020
4
Dallas, TX
I am hoping someone can help me here. I've been banging my head against a wall on this the past two days.

Background: The bearings / seal were shot on my ~10 year old WhisperFlo pump. The sound became ungodly, and it was slowly leaking water, so I bit the bullet on Thursday and pulled the motor to replace the seals and bearings. I had done this once before, about 4 years ago, so the process was not too painful this go-round.

Yesterday, I re-installed the motor, filled the basket with water, and turned the pump on, but I could not get the pump to prime. It was 97 degrees outside, and I ended up needing to re-run the electrical with new wiring because chips of the plastic wire casing had broken off where the wiring connects to the motor so, after an hour and a half of doing my own version of hot yoga (equipment / plumbing makes that area a tight fit), I opted to punt further troubleshooting until today. I watched a bunch of YouTube videos and read at least 10 different troubleshooting articles last night, just to ensure I wasn't missing something.

When I installed the seal plate o-ring from the "GO-KIT 32" package yesterday, it seemed to fit more loosely than I remembered the last time (like it was an inch bigger than it should have been). I realized after I came in that there was a second seal plate o-ring in the package (different part number), so this morning I disconnected the motor and installed the other one - which seems to be the right one as it fit much better. In any case, it did not fix the priming issue.

Here's what's happening -
  • Pump sucks up the water in the basket immediately. (I ran the hose with the basket lid off while troubleshooting.)
  • There's a little bit of air releasing through the (open) sand filter air bleeder valve.
  • I haven't let the pump run for more the 2-3 min but, as far as I can tell, it has not drawn in any water from the pool. (Maybe I just need to let it run longer?)
Troubleshooting done to date -
  • Turned the pump on briefly while the motor was disconnected to confirm the impeller was spinning as expected. (It was.)
  • Checked for cracks / damage around the pump that could cause air to leak.
  • Double-checked and lubed all of the o-rings. Replaced the lid o-ring. Confirmed that I hadn't missed any o-rings when putting things back together.
  • Tried priming with only the nearest skimmer line open. (It is only ~5 ft from the pump and always has the best suction.)
  • Tried letting the hose run in the basket for a few min before starting to reduce air in the lines. Also filled sand filter with water.
  • Went through basically all of the "usual suspect" recommendations you find in online troubleshooting guides with one exception - I have not bought one of those expandable bladder hose adapters to try to fill the line from the skimmer.
My pool runs all-year, so the last time the pump was fully de-pressurized was when I replaced the bearings about 4 years ago. When I empty the strainer basket, it typically only takes 30-45 sec for the pump to fully re-prime itself.

Are there any other suggestions? How long can it let the pump run with just the water that will stay in the intake basket? (I was hesitant to damage it from letting it run too long.)

Your help and suggestions are greatly appreciated!
 

Underwood

New member
Aug 8, 2020
4
Dallas, TX
Update: I bought a "cleaner bladder" attachment from Lowes, and it was a massive failure.

I turned the far skimmer and main drain suction lines off, then put the bladder attachment (connected to the water hose) in the "near" skimmer (~5 ft, at most, from the pump). I followed the instructions for the attachment, but the skimmer plumbing wouldn't allow the hose/attachment to be fully inserted into the pipe. I let the water run for a few minutes, with no evidence of water making its way up to the pump, then the bladder thing exploded. :mad:
 

Underwood

New member
Aug 8, 2020
4
Dallas, TX
I disconnected the motor for the second time today to triple-check the seals and connections. While I was at it, I ran the pump for a few seconds with the diffuser off to make sure the impeller was moving properly. Still no luck getting the pump to prime though.

All of the connections seem clean / good. I am at a loss for why this pump won't prime. I tried the "spray water over the pump and suction connections" method with the pump running, but it made no noticeable difference. The only different I could tell this time around, after reconnecting everything, was there seemed to be a bit more air coming out of the bleed valve, but it hot outside, so I guess some of that could just be the air trapped in the filter heating and naturally wanting to make its way out through the top.

At this point, I'm wondering if something in the suction-side plumbing developed a leak with the jostling to disconnect and reconnect the motor. (Besides needing a brand new pump, that would be a worst case scenario for me because there's no room to cut and replace piping due to how tight the connections are.)

Any thoughts?

Motor Impeller.jpg

Volute.jpg

Pump Setup.jpg