Do I Need to Evacuate Every Port on a Multi-Zone Mini Split Indoor Unit?Updated 2 months ago

Yes — every indoor unit’s line set must be properly evacuated before charging the system. There are two common approaches:

1. Step-by-step method:

   • After connecting each indoor unit, perform a vacuum on that unit’s line set before moving on to the next.

   • This ensures each unit’s lines are fully evacuated and allows for easier leak detection during installation.

2. All-at-once method:

   • If all indoor units are already installed and connected, you can pull a single vacuum from the outdoor unit’s service port, which evacuates all connected indoor units simultaneously.

   • Make sure all flare connections are tight and unused ports are closed and capped.

Key Points:

• Never open a port that is not yet connected to an indoor unit.

• Proper evacuation removes air and moisture, preventing system damage and ensuring optimal performance.

• Both methods achieve the same goal: every connected indoor unit is properly evacuated.