From which point is it desirable to fill the system?

From which point is it desirable to fill the system?

• A. From the lowest point.
• B. From the highest point.
• C. From the midpoint of the system.
• D. From the pump discharge.

Answer: (A)

When filling a fluid system, start at the lowest point to purge air efficiently. Gravity makes air rise to the top, so introducing liquid at the bottom pushes any trapped air up toward the highest vented point where it can escape. This helps achieve a complete fill with minimal air pockets that could hinder circulation. Filling from the highest point would trap air in the lower sections, and filling from the middle or from the pump discharge doesn’t reliably purge air from the entire loop.

When filling a fluid system, start at the lowest point to purge air efficiently. Gravity makes air rise to the top, so introducing liquid at the bottom pushes any trapped air up toward the highest vented point where it can escape. This helps achieve a complete fill with minimal air pockets that could hinder circulation. Filling from the highest point would trap air in the lower sections, and filling from the middle or from the pump discharge doesn’t reliably purge air from the entire loop.