Troubleshooting by Remote Controller SiME281501E151 Service Diagnosis4.45 Transmission Error between Indoor and Outdoor Unit /Piping and Wiring Mismatch / Refrigerant ShortageError Code UFApplicableModelsRZQMethod of ErrorDetectionCheck the transmission between the indoor and outdoor units with a micro-computer when thepower turned ON.Detect by checking the following temperature differences during compressor operation.A: Difference in temperature detected by the indoor heat exchanger thermistor (R2T) andthe indoor suction air thermistor (R1T)B: Difference in evaporating temperature (Te) (or condensing temperature (Tc) duringheating operation) detected by the indoor heat exchanger thermistor (R2T) and thecompressor sensorError DecisionConditionsWhen the transmission wiring between the indoor and outdoor units is incorrectWhen the following conditions continue for 20 minutes during compressor operationA: R2T – R1T < 4ºC, andB: R2T – Te (or Tc during heating operation) > 14ºC (24ºC during heating operation)SupposedCauses Defective transmission wiring between the indoor and outdoor units Mismatching of wiring and piping Refrigerant shortage Clogged refrigerant piping systemTroubleshootingRefer to P.161.Refer to P.163.Is theconnection oftransmission wiring andpiping between the indoor andoutdoor unitsmatched?Match the connection of thetransmission wiring and pipingbetween the indoor and outdoorunits.NOIs the refrigerant levelproper?Recharge a proper amount ofrefrigerant after refrigerantrecovery and vacuum drying.NOYESCHECK 12Check the refrigerant pipingsystem for clogging.CHECK 10Does "UF"appear when the power isturned ON?Correctly connect transmissionwiring between the indoor andoutdoor units.YESCaution Be sure to turn off the power switch before connecting or disconnecting connectors, or parts may be damaged.The phase of transmission wiringbetween the indoor and outdoor unitsis incorrect.NOYESCHECK 10CHECK 12
