Bitzer can often recover data for units back to the 1980s from microfilm archives—but this takes 3–5 business days.
"The 'B' variant has a known issue—the oil return port gets sludged if the refrigerant grade was R-404A with poor maintenance. But we switched to R-448A three years ago. The sludge would have dried and cracked. That crack would have lodged a fragment into the pressure relief valve." bitzer compressor serial number check