Hayward super pump - electric humming noise at start

[inca99]

I started up my pump for the first time this season (StaRite System3 with Hayward 1HP super pump). After a second or two of an electric humming noise and no flow, I figured the 3 year old pump had probably seized, so ordered a replacement pump (Century). After installing the new pump, with the included package of new seals - at first turn on, I am getting the same humming noise with no flow. As a side note, when I replaced the impeller on the new motor, I hand-tightened it using an open box wrench at the back end to secure the shaft. The impeller turned freely, but not easily (it did not "spin" easily by itself). I don't know if this is normal or if it has been over tightened, or if this even has anything to do with why it's not turning when I power it up.