If your pump system is functioning correctly, priming should only be required when the pump loses prime due to factors like air leaks, dry running, or improper sealing of the foot valve. Self-priming pumps automatically reprime after a loss of prime. Regularly inspect your pump for leaks or obstructions to minimize the need for priming. For non-self-priming systems, priming may be required after maintenance or long periods of inactivity.