5 Common Causes of Pool Pump Prime Loss

Loose or dried-out pump lid O-ring Remove the O-ring, clean the groove, lubricate with silicone pool lube, and reseat it. This fixes more than half of prime loss cases.

Cracked pump lid A cracked lid lets air in. Replace it rather than trying to seal it.

Bad valve gasket before the pump A worn or misaligned gasket on the suction side creates an air leak. Inspect and replace if necessary.

Low water level in the pool If the water drops below the skimmer opening, the pump sucks air. Top off the pool to restore prime.

Leak in underground suction piping This requires a professional to locate and repair. Test by pouring water over joints while the pump runs—if prime catches, you found the leak.