Centrifugal pumps are widely used in swimming pools as part of the recirculation system that sucks water from the swimming pool through the drain and them pumps it back into the pool after filtration. The present invention relates to a centrifugal pump for swimming pools that can accommodate impellers of varying size to attain the proper flow rate for varying circumstances. The centrifugal pump of the present invention also includes a deflector that improves the priming of the pump so as to eliminate or reduce the risk of heat and friction damage to the impeller.