What can be circulated through an R-11 or R-123 system to open the system for a nonmajor repair?

When dealing with R-11 or R-123 systems, it's essential to understand how these refrigerants operate and the implications of opening the system for repairs. During nonmajor repairs, the system needs to be opened in a manner that does not compromise its operational integrity or safety.

The circulation of hot water serves a specific purpose. It helps maintain a safe temperature and pressure environment within the system while performing the repairs. Hot water can also help keep the system components warm, preventing any condensation from forming inside, which can lead to contamination issues when moisture interacts with refrigerants.

On the other hand, using refrigerants or air can introduce problems. Refrigerants would require recovery processes to ensure they are safely handled and removed from the system. Air can lead to contamination and introduce moisture, which is particularly detrimental in refrigeration systems. Cold water, while potentially safe, does not provide the necessary heat to prevent the issues that hot water circumvents.

Therefore, hot water is the most appropriate choice for safely opening the system for nonmajor repairs, maintaining both efficiency and integrity in the process.