Turn on pump and it only has a humming sound. Motor does not start

a humming noise is a frequency noise meaning the motor is not running
check / replace the start/run capacitor for the pump motor
call an electrician for a proper diagnosis

Could be 2 reasons. If the pump is on and you are hearing a humming noise, it could be a bad capacitor. The capacitor is what starts the pump by giving it a kick start of electricity.

It could also be a seized motor, when it tries to start, it will also make a humming sound, and eventually trip the breaker.

The way to test if it seized is try to turn the motor by hand (Make sure the power is off). If the motor can't turn then it's seized.

sounds as if pump has stuck start winding switch , try giving Motor not the pump a sharp knock with a rubber mallet when you 1st turn on , this might jar it loose if not a new motor might be needed , if motor was larger then say 2hp then id say get it fixed at a motor repair shop due to cost saving but smaller sizes it's not worth it most times

A humming sound typically is caused by a locked pump, the motor is trying to turn but something is preventing it to start. It could be a bad bearing or some debris in the impeller. However the starting winding switch or also the winding itself could already be burned. The pump has to come out in any case.

3 THINGS QUICK.. RUN CAPACITOR THIS IS LOCATED ON TOP OF MOTOR HAVE IT CHECKED. OR START SWITCH DIRTY OR STAR CAPACITOR BAD.. SEARCH YOUR AREA FOR YOUR LOCAL POOL PUMP MOTOR REPAIR GUY WITH FREE TESTING.. WARNING THESE CAPACITORS HOLD HIGH VOLTAGE AND WILL NEED TO BE SHORTED ! USE A DRY RAG AND COVER CAPACITOR THEN SHORT WITH SCREWDRIVER

Sounds like its frozen and causing a very heavy load on your circuit. If the motor gets hot within seconds, its shot and needs replacing. Have you attempted to turn the motor over by hand ?

This could be anything from a stuck impeller to bad windings in motor. If you open the pump at the lock ring and remove the difusser from the impeller you can see if you can spin the impeller, If it won't move is it something holding the impeller up remove it. If notit is probally a bad bearing and you should replace the motor. If the Impeller turns try turning it on and caerfully try to spin before it kicks the breaker. If it is sort of stuck and does not want to turn the motor is bad and needs to be replaced. If it spins and won't start same thing, If it spins and starts it is probally a start capicator. Shut the power off at the breaker remove the back of the motor the capacitor will be a small black or silver cylinder with 2 or 3 wires clipped to it. Remove this and take it to a motor shop and get an exact duplicate. and that should fix it. When putting back together be sure to lube all "O"rings and refill with water. Hope this helps.

I HAVE A ZOELLER PUMP AND THE IMPELLER WONT TURN I TAKE A SCREW DRIVER AND TURN IT AND IT WORKS STOP THE PUMP AND IT HUMS CAN THE IMPELLER COME OFF IF IT DOES HOW DO YOU TAKE IT OFF.

Prime the pump. If it still just hums, try to turn the impeller. If the impeller is not jammed, and the motor hums or it doesn't start at all, the motor may be bad. Check for correct voltage of the incoming power wires inside the motor connection housing. Sometimes turning the circuit breaker off, then back on will fix it.

  Sounds like something in pump.  This is causing motor to hum and not turn.  Motor is going off on thermal overload.  This is why the humming stops.  It may be possible for you to tilt washer back and access pump.  Remove clip on bottom and top and pull pump off motor.  Try and turn pump.  Remove hoses and see if you can see obstruction.