Whisperflow Hums won't Start

All,

We had a great stretch of 80F weather here in St. Louis and I opened earliest ever this year. Anyway, had a problem with my Pentair Whisperflow pump and thought I'd share.

Turning it on for the first time this season, the pump would hum but impeller wouldn't turn. Last year had the same thing happen, but just turning the pump off then on a couple of times fixed it -- not so lucky this year. But, after doing just a little reading the consensus was something might be stuck in the impeller. My hands were too big to reach in and find an obstruction or spin the impeller manually. I removed the 10 bolts that attach the front (water) side to the electric motor in back. Then you have to remove 2 small, long bolts with an Allen wrench that hold the housing over the impeller. Once I got to this point, I could see there was no obstruction -- the impeller was just "stuck" and needed to be manually spun back and forth. THAT DID THE TRICK!

Put everything back together and its been running fine.

One question for anyone who knows about these pumps -- is there anything I should be lubricating in them to help this from happening, and to keep down the wear and tear?

Didn't even know there was an O-ring in the impeller on the "water" side that needed lubrication until I got into this. It was in good shape, but still gave it a good lub like all the other O-rings I do at opening.

Thanks,
-Craig

Craig,
Something is puzzling. Was the hum that you heard loud or kind of low? Reason I ask is that normally there is a large current through the starting winding when the motor is stalled. Doesn't take too long, less than 30 seconds I would think, to trip the thermal breaker or the house breaker feeding the thing. This would be a loud hum. A low level hum indicates the starting winding is not powered which would point to the centrifugal starting switch not making contact. This is quite common when the motor hasn't been run all winter or for long periods of time when exposed to the elements. If the starter kicked in like it should I would think the torque developed would be enough to overcome any sticking, unless something was really really stuck. I've heard of bearings freezing up but once freed they would make a lot of noise. I'm not familiar with that pump but any O-ring would not be used to seal a moving assembly. The water shaft seal is something else, ceramic I believe. I'm suspecting the low hum scenario and with you taking things apart you jostled the centrifugal switch and it made contact and started working again. I've suggested people whack the motor on the rear with a 2x4 in these cases with the shock causing the switch to make contact. People have done this successfully and I have to do it periodically with the motor on my drill press. When this happens you should clean the contacts. Anyhow, glad all is working again. Enjoy swimming.

Here is the link to that thread:

http://www.poolforum.com/pf2/showthread.php?t=4800

Al