What critical step in the setup helps ensure the system's operational integrity?

Conducting a leak check is crucial in the setup of water treatment systems because it helps verify the integrity of the entire plumbing installation. During the leak check, the technician inspects all connections, fittings, and components for any signs of water escaping. This step is essential to prevent ongoing water waste, avoid potential damage to surrounding areas, and ensure that the system will operate efficiently without any interruptions caused by leaks.

While faucet installation, assembly of the manifold, and tank placement are important parts of the overall setup, they do not directly address the operational integrity of the system in the same way that a leak check does. A leak could undermine the function of the system, even if all other components are installed correctly. Therefore, performing a thorough leak check serves as a preventive measure to establish that the installation can function without issues, ensuring the reliability and longevity of the system.