The pump is running, water is not moving. Does not seem like the impeller moves. Just found it before heading to work, so I did not have a chance to explore more. The pump is on and it seems like the motor is working, making a humming noise and slightly heated. The water in the chamber is not moving. What is my next troubleshooting step? The pump was ok for three years or so with no issues. It's a super-flow Heyward pump.