A vacuum pump is a tool used to remove air and moisture from the refrigerant lines before charging the system. This is a critical step for any Multi-Zone installation to prevent system failure. You can find professional-grade pumps in our Other Accessories collection. Moisture in the lines can freeze and block the expansion valve, leading to a breakdown. Running the pump until a deep vacuum is achieved ensures a clean environment for the refrigerant. This is a must-have tool for serious HVAC installers.