5 Recovery Completion and Troubleshooting
Learn how to verify refrigerant recovery, handle and document recovered refrigerant, and respond safely to common recovery problems.
Required evacuation levels
A job is complete only when the appliance has reached its required , refrigerant is safely contained, and the equipment and records are left in a known condition. Elapsed time or a falling -machine inlet pressure alone does not prove that is complete.
Before opening an appliance, identify its pressure category, full charge, and required . For stationary appliances other than small appliances, MVACs, and MVAC-like appliances, recover all liquid refrigerant to the applicable level and verify that level before opening the appliance. Use certified equipment according to its manufacturer’s instructions.
For equipment using machinery manufactured or imported on or after November 15, 1993, the principal EPA evacuation levels are:
Very-high-pressure appliance: .
High-pressure appliance with a full charge under : .
High-pressure appliance with a full charge of or more: .
Medium-pressure appliance with a full charge under : .
Medium-pressure appliance with a full charge of or more: .
Low-pressure appliance: .
Vacuum readings are relative to standard atmospheric pressure unless marked absolute. A reading of is atmospheric pressure, not a deep vacuum. Small appliances have separate EPA requirements: percentages depend on compressor condition and equipment age, or the appliance may be evacuated to .
Verify completion safely
Use an appliance-side gauge to verify the required level. Follow the -equipment manufacturer’s procedure; neither a timer nor the unit’s inlet gauge substitutes for measuring the appliance.
A practical completion check proceeds as follows:
Confirm setup and operating conditions. Check hose and valve positions, service connections, filter-drier condition, machine airflow, power supply, and the machine’s operating instructions. Confirm that the refrigerant is correct and that the is suitable and approved.
Recover to the required level. Monitor appliance-side pressure with an appropriate gauge and follow the equipment manufacturer’s procedure.
Allow pressure to stabilize and recheck. After isolating the appliance as directed by the -equipment manufacturer, watch for . If pressure rises, refrigerant may still be boiling out of oil or remaining in another system section. Continue and recheck as appropriate; do not open the circuit until the required level is verified. Account for isolated sections and trapped liquid that may not be connected to the path.
Isolate and secure. Close valves in the prescribed order, avoid trapping refrigerant between closed valves, and disconnect hoses using low-loss practices. Check connections for leaks, then cap or secure service ports and cylinder valves.
Document the result. Record the final pressure or and any exception, limitation, or abnormal condition.
If a leak prevents reaching the normal level, apply the EPA exception only under its conditions: isolate leaking and non-leaking components where possible, evacuate non-leaking portions to the required level, and evacuate leaking portions to the lowest attainable level that does not substantially contaminate recovered refrigerant, not exceeding .
Handle cylinders and refrigerant
Use a cylinder intended and rated for refrigerant , compatible with the refrigerant, and in acceptable condition for filling and transport. Identify its tare weight and marked maximum gross weight. Weigh it during and after , and never exceed its permitted filling limit. Do not estimate fill visually or assume every cylinder has the same safe refrigerant capacity. Applicable hazardous-material rules govern cylinder filling and transport, and the cylinder must be safe to fill.
Keep different refrigerants separate. Do not knowingly combine them in one cylinder: mixing can make the contents difficult or impossible to reuse and may require specialized handling. Clearly identify the refrigerant type and relevant contents or status under applicable shop and transport procedures. If refrigerant is unknown or suspected to be mixed or contaminated, segregate it and mark it accordingly rather than treating it as clean, identified refrigerant.
Document and transfers
A useful service record can include:
Appliance location or identifier, date, technician, and reason for .
Refrigerant type, if known; source appliance; and any uncertainty or suspected contamination.
Cylinder identifier, starting and ending weights, amount recovered, and cylinder gross-weight check.
-machine identification, final appliance pressure or , and any or other unusual condition.
Where the refrigerant went: returned to the same appliance, held for reuse by the same owner, or transferred for or destruction; include the recipient and transfer date when applicable.
Some entries are specifically required by regulation, while others are sound service practice. For example, EPA requires technicians disposing of appliances with a full charge of more than and less than to keep specified records for three years. These include appliance location, date, refrigerant type, monthly recovered quantities, and transfer details. Check the applicable rules for the appliance and refrigerant; recordkeeping requirements are not necessarily identical for every service job.
Distinguish refrigerant processes
, , and describe different processes. removes refrigerant into an external container; cleans refrigerant for reuse in equipment owned by the same person; reprocesses refrigerant to applicable purity specifications.
Under EPA Section 608 rules, recovered refrigerant may generally be returned to the same system or another system owned by the same person. If refrigerant changes ownership, it must be reclaimed by an EPA-certified reclaimer before resale. does not automatically purify refrigerant or make it suitable for unrestricted resale.
Troubleshoot common problems
Use the symptom to guide checks, but follow the equipment manufacturer’s instructions and do not bypass safety devices.
is unusually slow or stops early: Check for closed or incorrectly positioned valves, restricted hoses or filters, poor machine airflow, inadequate power, or a full or overheated cylinder. Confirm the setup against the manufacturer’s instructions. Do not bypass a pressure switch or other safety device.
Appliance pressure rebounds after : Allow conditions to stabilize and consider refrigerant boiling out of oil, migration from another section, or a trapped volume. Reconnect and continue as appropriate, then verify the required level again.
Cylinder pressure is higher than expected: Consider cylinder temperature and refrigerant identity. Let the cylinder stabilize before interpreting pressure against a pressure-temperature relationship. Do not vent refrigerant to reduce pressure. If the cylinder may be overfilled, leaking, or unsafe, stop handling it and follow applicable emergency and hazardous-material procedures.
Recovered refrigerant appears contaminated or its identity is uncertain: Keep it separate, identify the uncertainty, and do not mix it with known refrigerant. Arrange appropriate testing, , or disposal through qualified channels.
The required cannot be reached: Check the system for leaks and verify the path and instruments. Apply the relevant regulatory exception only when its conditions are met, and record the limitation and the level actually attained.
Frequent procedural errors include using the wrong refrigerant cylinder, mixing refrigerants, exceeding cylinder limits, failing to check cylinder condition or weight, stopping when only the machine indicates low pressure, skipping the appliance-side completion check, and opening the system before confirming the required .