Oh no! Impeller is sticking


LifeTime Supporter
Mar 31, 2008
Central VA
I noticed when I opened my pool last month that my pump wasn't quite working right...I have a Whisperflo 1hp Pentair pump.
I figured out that the impeller (which is all plastic, by the way) wasn't rotating, so I removed the bolts and forced the impeller to turn manually, then re-assembled the pump and voila-it worked. I'm on a timer, and I noticed today that the problem had returned (probably has been there all along, but I haven't had much time to observe it until today). In fact, after about 30 seconds something tripped and the pump turned itself off.
I know I've probably just about ruined my pump, but is there a way to lube the inside of the pump, or the impeller, to squeeze a little more life out of it?


TFP Expert
LifeTime Supporter
May 3, 2007
Pleasanton, CA
Pool Size
Salt Water Generator
Sounds like it could be either a starting capacitor or maybe some bad bearings but the bearing would probably make a lot of noise. I would try replacing the capacitor to see if that works.


LifeTime Supporter
Mar 31, 2008
Central VA
Just a quick follow up on the impeller sticking...I have my pump coming on (by timer) several times a day, and I noticed last night that when the timer powers up, the impeller will stick and the pump will hum (like it's sticking) for a few seconds, then trip off. It will then (after it cools down, I guess) try again and again until the impeller releases, and the pump will then stay on for the duration.
Still sound like a starting capacitor? thanks again for the help.


May 31, 2009
My 3/4HP Whisperflo (WFE-3) ran dry and I just took the motor off two days ago to inspect.

The thermal breakers on these motors will shut down, cool and restart by itself, which imo, is dumb!

These pumps are great, powerful and quiet but getting to that impeller can be a pain in the Rear...

To replace the shaft seals you need to take off the big seal plate. The bottom 2 stainless steel bolts were frozen solid on mine. I had to get some heat to those bolts, some liquid wrench and a breaker bar to these to remove. Be very careful or you'll break the heads off and then you'll need to buy a new seal plate.

The motor was fine (no damage to bearings or shaft) so I replaced the ceramic shaft seals and the seal plate gasket.

If the motor wasn't making loud noises, maybe you should do the same as I and see if there's a bunch of stuff wrapped around the impeller or the impeller is chipped or cracked and a piece is jamming the rotation.

If the motor turns easy with little effort and the impeller is undamaged, I'd replace the shaft seals, seal plate gasket and the capacitor then reinstall.

Note: To remove the impeller on the Magnetek motor, you need to pry off the little 1 1/2" diameter shaft cap at the back of the motor and block the shaft from rotating with a vice grip. Don't try to remove the entire motor end cap. I made that mistake and broke one of the four cap bolts. URGHHHH!
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