17START−UPTest OperationPerform test operation after completing gas leak and electricalsafety check. See the indoor unit installation instructions andowner’s manual for additional start up information.SYSTEM CHECKS1. Conceal the tubing where possible.2. Ensure the drain tube slopes downward along its entirelength.3. Ensure all tubing and connections are properly insulated.4. Fasten tubes to the outside wall, when possible.5. Seal the hole through which the cables and tubing pass.OUTDOOR UNIT1. Are there unusual noises or vibrations during operation?Explain the Following Items To Customer (with the aid of theOwner’s Manual):2. Explain care and maintenance.3. Present the Owner’s Manual and installation instructions tocustomer.OUTDOOR UNIT DIAGNOSTIC GUIDESThis unit has on−board diagnostics. Error codes are displayed on the wired remote controller and the outdoor unit microprocessor board withcolored LED lights. Table 14 explains the error codes on both.Table 14—Outdoor Unit Error DisplayDISPLAY LED STATUS IDU Error IDU ErrorE0 Outdoor EEPROM malfunction F4 E6E2 Communication malfunction between indoor and outdoor units E1 E2E3 Communication malfunction between IPM board and outdoor main board —— ——E4 Open or short circuit of outdoor temperature sensor (T3、T4、T5、T2B) F2 E6E5 Voltage protection P1 P0E6 PFC module protection —— ——E8 Outdoor fan speed has been out of control (Only for DC fan motor models) F5 ——E9 Wrong wiring connection of 24K indoor unit —— ——F1 No A Indoor unit coil outlet temp. sensor or connector of sensor is defective —— ——F2 No B Indoor unit coil outlet temp. sensor or connector of sensor is defective —— ——F3 No C Indoor unit coil outlet temp. sensor or connector of sensor is defective —— ——F4 No D Indoor unit coil outlet temp. sensor or connector of sensor is defective —— ——F5 No E Indoor unit coil outlet temp. sensor or connector of sensor is defective —— ——F6 No F Indoor unit coil outlet temp. sensor or connector of sensor is defective —— ——P0 Temperature protection of compressor top P2 P3(P1)P1 High pressure protection —— ——P2 Low pressure protection —— ——P3 Current protection of compressor —— ——(P2)P4 Temperature protection of compressor discharge —— ——P5 High temperature protection of condenser —— ——P6 IPM module protection P0 E5