Pool Pumps - Motor Hums
Pump hums and shuts off
Sometimes a pump motor will make a humming noise and then shut off with a "click". The problem is that the motor is failing
to start turning. With a stationary rotor, the motor quickly overheats and the temp sensor cuts it off. If the power is left on, the motor will cool down and
then go through the process over and over again.
There are a several possible causes for this:
If the start capacitor is bad, it will cause the motor to fail to begin turning. Many pool motors are replaced unnecessarily each year
because the owner or tech did not know to check for a bad capacitor. A new capacitor costs $25-$35 while a new motor costs $200 or more. The only way to
accurately check a capacitor is with a digital multimeter that will give an exact reading of capacitance. In the absence of a multimeter, you can try a new capacitor
of the same mF rating and see if it works.
If there is sand or other debris stuck between the impeller and the pump body, it can make it difficult for the motor to turn over. The
best way to check this is to turn the power off and attempt to turn the shaft of the motor by hand. If it will not turn, then disassemble the motor and check for
If the line voltage, as measured at the motor terminals is not within 10% of the specified motor voltage, then it can cause a pump motor to
fail to start. Sometimes the problem is that the wiring to the motor is insufficient, causing a voltage drop.
This is a catch-all category, we admit, but sometimes pool motors get old and start overheating. At this point it is best to simply
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