Before recovering refrigerant from an R410A unit using a recovery unit that previously contained R-22, what must be done?

The appropriate action to take before recovering refrigerant from an R410A unit using a recovery unit that previously contained R-22 is to remove the R-22 from the recovery unit and change the filter. This is essential because mixing refrigerants can create dangerous conditions and affect the efficacy of the recovery process.

R-22 and R-410A have different chemical properties, and introducing them together can lead to contamination. The recovery unit needs to maintain its integrity and effectiveness in recovering the specific refrigerant type. By completely removing the R-22, you help prevent any potential chemical reactions and ensure that the recovery unit is prepared to handle the R-410A without residual effects from the past refrigerant it contained. Changing the filter also ensures that any impurities that may have accumulated during the use of R-22 are eliminated, contributing further to the safe and effective recovery of the new refrigerant.

Implementing this process aligns with best practices and safety protocols laid out by EPA regulations, promoting environmental protection and efficient system operation.