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Why Does My Pool Pump Make a Humming Noise?

By Elizabeth Ireland ; Updated September 21, 2017
Replacing a humming pool pump is an investment in a clean pool.

Pumps are one of the more expensive components of a swimming pool filtration system. When they are working, the pool is clean and leaf free, but when pool pumps begin to go bad, they can be a source of serious aggravation. A humming pool pump is an unhealthy pool pump. The hum indicates that the motor is unable to turn over. Without a properly functioning motor, the pump cannot do its job. Often, the hum is followed by a complete shutdown of the pump due to overheating.


Dirt or other debris might be jamming the pump motor impeller. If you cannot turn the impeller by hand -- after disconnecting the pump from its power source -- you will need to find the source of the jam and remove it. A jammed impeller is one of the easier pump fixes.


If the voltage to the pump's motor is too low – often caused by insufficient wiring – the pump will not turn over. If you try to run a 220-volt motor on a 110-volt electric line, the pump will just hum.


The pool pump’s start capacitor – a fairly inexpensive part that acts a bit like a back-up battery – might be malfunctioning. If the capacitor is leaking oil or is dusted with a white residue it has gone bad and will need to be replaced.


The lubricant, or grease, in the pool pump motor can be displaced by water through a leak in the shaft seal, allowing the bearing to grind against one another. This can create a screeching or humming noise.


About the Author


Elizabeth Ireland began writing professionally in 1997 as a reporter and columnist with the "Lancaster (Pa.) Sunday News." She now serves as the marketing and communications manager for Elizabethtown College, where she earned an associate degree in corporate communication. Ireland also covers rock climbing, cycling, the outdoors, home remodeling, relationships, cooking, higher education, fitness and the environment.