Which condition prompts removal of refrigerant from the condenser outlet in a system with a receiver?

• A. The condenser is below the receiver
• B. The receiver is below the condenser
• C. The system is off
• D. During startup

Answer: (A)

When a receiver and condenser are used together, liquid refrigerant is stored in the receiver and fed from the condenser outlet into the receiver. If the condenser sits below the receiver, gravity tends to push liquid from the receiver back toward the condenser through that outlet when the system is stopped or when pressures favor reverse flow. To prevent the condenser from filling with liquid and creating potential flooding or slugging issues when the system restarts, refrigerant is removed (relieved or isolated) from the condenser outlet under that vertical arrangement. The other conditions don’t inherently cause this backflow risk, so the key factor is the condenser being lower than the receiver.