5 Signs Your Pool Pump Needs a New Capacitor

The pump hums but the impeller doesn’t spin A humming motor that won’t start is the classic symptom of a failed capacitor. The capacitor stores charge to give the motor a starting jolt, and when it fails, the motor gets power but can’t move.

The pump tries to start but stops quickly If the impeller spins a little then stops, or runs at slower speeds while struggling to keep prime, the capacitor is likely weak or dead.

The capacitor looks swollen, cracked, or leaking Visual damage like bulging, cracks, or goo leaking out means the capacitor is toast. A burned smell is another clear sign.

A multimeter shows low or no capacitance You can confirm the failure by testing with a multimeter, but if you have the hum-without-spin symptom and the pump hasn’t been running, just swap the capacitor.

The impeller spins freely by hand Before replacing the capacitor, rule out a stuck impeller. Turn off power, remove the pump lid, and spin the impeller by hand. If it moves freely, the capacitor is the problem.