Pump Hums, Capacitor Good

[walker3733]

Ok, so my pump just hums and wont start. The pump has been running fine all summer and went out last week. So I replaced the capacitor and everything was running fine until today. I stopped it so I could start up the hot tub and it wouldn't start again. I am back to the humming. I have tested the capacitor and it is good. I also put a meter on my pump and I am getting voltages ranging from 225 to 26 when I am trying to start it. I am at a loss here and hoping someone can help. A little background on the pump itself. It is a 2.5 HP Pentair Challenger. I believe it is the original pump and motor to the pool built in 2004, it has at least been here since I bought the house in 2010. I have absolutely no problem buying a new motor, I just want to make sure it isn't just a $20 part that is broken instead of a $300 motor.

Thanks In Advance,

Justin

 

[JoelFitz]

There should be shaft access on the rear of the motor either under a metal cap or plastic hex do-hickey. Remove and use a 1/2 end wrench to turn the motor shaft. Is it binding up at all? If so (or if not) try to start it again. Next remove the clamp and inspect the diffuser, then remove the diffuser and inspect the impeller. If the capacitor is good, with the motor apart from the pump assembly, switch it on/off real fast...it should start. If it does check everything again because something is bound up in the assembly. If it still hums you prob. need a new motor.