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Mixed or Wrong Refrigerant — Identify and Recover Immediately

Likely causes

Adding wrong refrigerant — e.g., R-22 added to R-410A system

Check: Use refrigerant identifier for precise measurement — shows composition. Without analyzer, compare equilibrium pressure vs ambient temp against PT chart for known refrigerant — mismatch indicates mix.

What to do: 1) Stop immediately — continued operation damages incompatible oil and compressor. 2) Full recovery; label cylinder 'Mixed Refrigerant' and never reuse in another system. 3) Evacuate 30 min + recharge by weight. 4) If compressor oil discolored, consider oil change.

Oil incompatibility — mixing POE/PAG/mineral oil causes lubrication failure

Check: Oil standards by refrigerant: R-22/R-134a (legacy) = mineral; R-134a (new)/R-404A/R-410A = POE; R-1234yf = special PAG/POE. Inspect oil color — black or oxidized = incompatible or contaminated.

What to do: 1) Oil analysis (lab or color/viscosity comparison) — confirm mix ratio. 2) On incompatibility, full oil change is required. 3) System flush — clean lines, coils, compressor interior. 4) New oil + new refrigerant + new filter-drier + evacuate + recharge by weight. 5) Expensive job — do it right the first time.

Field tip

Mixed/wrong refrigerant errors are 100% human-caused. Triple check before charging: nameplate + cylinder label + manifold's selected refrigerant. 30-second triple check prevents catastrophic system damage.

All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.

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