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Browse codes (841 in current scope) , All codes in scope , Carrier · 44, Motor Communication Fault Carrier · 41, Blower Motor Fault Carrier · 15, Blower Motor Lockout Carrier · 37, Heater Output Sensed On Carrier · 13, Limit Circuit Lockout Carrier · 14, Ignition Lockout Carrier · 21, Gas Heating Lockout Carrier · 22, Abnormal Flame Proving Signal Carrier · 23, Pressure Switch Did Not Open Carrier · 24, Secondary Voltage Fuse Open Carrier · 33, Limit Circuit Fault Carrier · 45, Control Circuitry Lockout Carrier · VC VOLTAGE AT STANDBY, Voltage at Standby Carrier · HI CAPACITY COMPRESSOR LOCKOUT, High Capacity Compressor Lockout Carrier · AF, Airflow Restrictions Detected Carrier · HP, High-Pressure Lockout Carrier · LP, Low-Pressure Lockout Carrier · OP, Outdoor Temperature Sensor Fault Carrier · 101, Communication Fault Carrier · 181, Low System Charge Carrier · 323, Outdoor Fan Fault Carrier · Constant On, No Demand / Standby Carrier · 1, 1st Stage Compressor Carrier · 2, 2nd Stage Compressor Carrier · 16, System Communication Failure Carrier · 25, Invalid Model Plug Carrier · 31, Hi Pressure Switch Trip Carrier · 32, Low Pressure or Discharge Temp Switch Trip Carrier · 46, Low Line Voltage (Brown Out) Carrier · 47, No Power Present at O/D Unit Carrier · 53, Outdoor Temp Sensor Failure Carrier · 55, Outdoor Coil Sensor Failure Carrier · 56, Thermistors (Outdoor & Coil) Out of Range Carrier · 71, Low Stage Thermal Cutout Carrier · 72, High Stage Thermal Cutout Carrier · 73, Contactor Stuck Closed Carrier · 74, No Power at Compressor Carrier · 81, Low Stage Thermal Cutout x 3 Carrier · 82, High Stage Thermal Cutout x 3 Carrier · 83, Low Pressure Switch Trip x 3 Carrier · 84, High Pressure Switch Trip x 3 Carrier · H7, Indoor Unit Quantity Mismatch Carrier · P4, Compressor Protection Carrier · P6, IPM Fault Carrier · 00001, Low Fuel Level Warning Carrier · 00002, Low Engine Oil Level Warning Carrier · 00003, Low Coolant Level Carrier · 00004, Low Refrigerant Level Carrier · 00011, Check/Low Engine Oil Pressure Carrier · 00012, High Coolant Temp Carrier · 00013, High Discharge Pressure Carrier · 00015, Battery Voltage Too High Carrier · 00016, Battery Voltage Too Low Carrier · 00019, Low Fuel Shutdown Carrier · 00021, Technician Reset Required Carrier · 00031, Failed To Start – Auto Mode Carrier · 00041, Engine Stalled Carrier · 00053, Box Temp Out of Range Carrier · 00061, Door Open Carrier · 00073, No A/C Power – Check Cord Carrier · E3, Various Errors Carrier · Low--Pressure Switch (AC only), Low--Pressure Switch Carrier · High--Pressure Switch (AC & HP), High--Pressure Switch Carrier · Loss Of Charge Switch (HP only), Loss Of Charge Switch Carrier · FIRE SHUTDOWN, Fire Shutdown Alarm Carrier · FAN STATUS, Fan Status Fault Carrier · FILTER STATUS, Filter Status Warning Carrier · ECONOMIZER ACTUATOR COMMUNICATION, Economizer Actuator Communication Fault Carrier · IAQ SWITCH, Indoor Air Quality Switch Alarm Carrier · IAQ SENSOR, IAQ Sensor Fault Carrier · OAQ SENSOR, Outdoor Air Quality Sensor Fault Carrier · Communication Failures, Communication Failure Carrier · Phase Loss Protection, Phase Loss Protection Carrier · E1, Communication Error Carrier · 1 - Pause, 1st Stage Compressor Carrier · 2 - Pause, 2nd Stage Compressor Carrier · 11, Normal Operation Carrier · 57, Compressor Current Limit Carrier · 86, VFD Low Voltage Carrier · Err 33, Outdoor Heat Pump Communication Error Carrier · Err 35, Outdoor Unit Power Interruption Carrier · Err 71, Temperature Sensor Malfunction Carrier · Err 90, Thermostat Memory Error Carrier · Err 121, Invalid Data Error Carrier · Code 179, Flame Rollout Fault Carrier · Code 178, Furnace Lockout Carrier · Code 176, Ignition Failure Trane · MULTIPLE INDOOR UNIT CONFIGURATION FAULT, Multiple Indoor Unit Configuration Fault Trane · MULTIPLE OUTDOOR UNIT CONFIGURATION FAULT, Multiple Outdoor Unit Configuration Fault Trane · COMPRESSOR HEAT STAGES CONFIGURATION FAULT, Compressor Heat Stages Configuration Fault Trane · COMPRESSOR COOLING STAGES CONFIGURATION FAULT, Compressor Cooling Stages Configuration Fault Trane · GAS HEAT STAGES CONFIGURATION FAULT, Gas Heat Stages Configuration Fault Trane · ELECTRIC HEAT STAGES CONFIGURATION FAULT, Electric Heat Stages Configuration Fault Trane · HYDRONIC HEAT STAGES CONFIGURATION FAULT, Hydronic Heat Stages Configuration Fault Trane · NO INDOOR UNIT CONFIGURATION FAULT, No Indoor Unit Configuration Fault Trane · HEAT PUMP COMPRESSOR STAGES CONFIGURATION FAULT, Heat Pump Compressor Stages Configuration Fault Trane · ZONING DISCHARGE TEMPERATURE CONFIGURATION FAULT, Zoning Discharge Temperature Configuration Fault Trane · MULTIPLE ZONE PANEL CONFIGURATION FAULT, Multiple Zone Panel Configuration Fault Trane · ZONING STATIC PRESSURE CONFIGURATION FAULT, Zoning Static Pressure Configuration Fault Trane · NO PRIMARY ZONE PANEL CONFIGURATION FAULT, No Primary Zone Panel Configuration Fault Trane · 2 flash (Electromechanical), 1 Hour Lockout Trane · 3 flash (Electromechanical), Pressure Switch Trane · 4 flash (Electromechanical), TCO Open Trane · 5 flash (Electromechanical), Flame W/O Gas Trane · 6 flash (Electromechanical), Rollout Switch Open Trane · 7 flash (Electromechanical), W1 / W2 Swapped Trane · 2 flash (IGN), Flame Sense Lockout Trane · 3 flash (IGN), Pressure Switch Failure Trane · 4 flash (IGN), TCO Circuit Open Trane · 5 flash (IGN), Stuck Gas Valve Trane · 6 flash (IGN), Flame Rollout Open Trane · Off (Transmit LED), System Failure Trane · Receive LED Wink, No Communication Trane · Receive LED Off, Board Failure Trane · One blink (LED2), Emergency Stop Open Trane · 2 flashes (LED2), Diagnostic Present Trane · ON (Service J6-10), Clogged Filter Trane · PULSING (Service J6-10), Fan or Safety Fault Trane · PULSING (Cooling J6-8), Cooling Lockout Trane · PULSING (Heating J6-7), Heating Diagnostic Trane · 7 & 8 PULSING, Global Safety Fault Trane · PULSING (HEAT-VAV), SA Temp Sensor Failure Trane · PULSING (COOL-VAV), DTS Sensor Failure Trane · ON (COOL+SERVICE-VAV), Static Pressure Sensor Error Trane · ON (H+C+SERVICE-VAV), High Duct Static Trip Trane · LED 1 Off, System Failure Trane · LED 2 - 1 Flash, Communication Failure Trane · LED 2 - 2 Flashes, System Lockout Trane · LED 2 - 3 Flashes, Pressure Switch Failure Trane · LED 2 - 4 Flashes, TC01 or TC02 Open Trane · LED 2 - 5 Flashes, Flame Without Gas Valve Trane · LED 2 - 6 Flashes, Flame Rollout Open Trane · LED 3 Flashing, Cooling Failure Trane · LED 4 Off, Service Failure - Clogged Filter Trane · LED 4 Flashing, Service Failure - Fan Proving Trane · E0, Thermistor Error Trane · E3, Permanent Data Error Trane · E4, Input Voltage Error Trane · E5, RTC Error Trane · E7, Memory Error Trane · 79, Low-Pressure Switch Open Trane · 91, Communication Loss Trane · 126, Communication Malfunction or Lockout Trane · 158, Cold Evaporator Coil Trane · E1, Mini Split Communication Error Trane · E2, Sensor Failure Trane · 22, Soft Lockout Trane · 90, Equipment Recognition Error Trane · 26, Overheating Fault Trane · 89, Equipment Connection Error Trane · 184 08, Soft Lockout Shutdown Trane · 126 (950 Model), Low-Temperature Lockout Trane · 67.06, Suction Temperature Sensor Error Trane · CL2.067.00, Ambient temperature sensor fault Trane · CL2.067.01, Coil temperature sensor fault Trane · CL2.067.02, Liquid line temperature sensor fault Trane · CL2.068.00, Defrost Fault A Trane · CL2.068.01, Defrost Fault B and/or C Trane · CL2.068.02, Combined Defrost Fault Trane · CL2.079.00, Low-pressure cut-out short lock-out Trane · CL2.079.02, Low-pressure cut-out hard lock-out Trane · CL2.080.00, High-pressure switch short lock-out Trane · 18, 24V Sensing Error / Control Fault Trane · 50, Duplicate Outdoor Temperature Sensor Trane · 67, Temperature Sensor Fault Trane · 68, Defrost Fault Trane · 80, High Pressure Monitor Fault Trane · CL2.067.00 / 5 Flash / Fault A inputs, Ambient temperature sensor fault Trane · CL2.067.01 / 6 Flash, Coil temperature sensor fault Trane · CL2.067.02 / 11 Flash, Liquid temperature sensor fault Trane · CL2.068.00 / 2 Flash, Defrost Fault A Trane · CL2.068.01 / 3 Flash, Defrost Fault B and/or C Trane · CL2.068.02 / 4 Flash, Combined Defrost Fault Trane · CL2.079.02 / 7 Flash / ERR 79, LPCO Hard Lock-Out Trane · CL2.080.00 / 17 Flash / ERR 80, HPCO Short Lock-Out Trane · 2 flash, 1 Hour Lockout Trane · 3 flash, Pressure Switch Failure Trane · 4 flash, TCO Open Trane · 5 flash, Flame Without Gas Trane · 6 flash, Rollout Switch Open Trane · 7 flash, W1 / W2 Swapped Trane · One blink, Emergency Stop Open Trane · PULSING, Service/Fan Fail/Safety Active Trane · 1 flash, RTEM Actuator Fault Trane · 1, Plenum Fan Phase Failure Trane · 8, Plenum Fan Rotor Locked Trane · 2 flashes, CFMB Under Voltage Trane · 5 flashes, CFMB Over Current Trane · PRIMARY ZONE PANEL CONFIGURATION FAULT, Primary Zone Panel Configuration Fault Trane · ZONING CONFIGURATION INVALID, Zoning Configuration Invalid Trane · NO HUMIDITY SENSOR FAULT, No Humidity Sensor Fault Trane · NO OUTDOOR TEMPERATURE SENSOR, No Outdoor Temperature Sensor Trane · CONFIGURATION FAULT, Configuration Fault (Relay Panel/Outdoor Unit) Trane · ZONE TEMPERATURE SENSOR CONFIGURATION FAULT, Zone Temperature Sensor Configuration Fault Trane · ZONE SENSOR 1 CONFIGURATION FAULT, Zone Sensor 1 Configuration Fault Trane · ZONE SENSOR 2 CONFIGURATION FAULT, Zone Sensor 2 Configuration Fault Trane · ZONE SENSOR 3 CONFIGURATION FAULT, Zone Sensor 3 Configuration Fault Trane · ZONE SENSOR 4 CONFIGURATION FAULT, Zone Sensor 4 Configuration Fault Trane · ZONING NOT SUPPORTED – SYSTEM IS NOT OPERATIONAL, Zoning Not Supported Trane · ZONE BACKUP SENSOR CONFIGURATION FAULT, Zone Backup Sensor Configuration Fault Trane · HUMIDITY SENSOR MISSING, Humidity Sensor Missing Trane · DUPLICATE OUTDOOR STAGES CONFIGURATION FAULT, Duplicate Outdoor Stages Configuration Fault Trane · MISSING OUTDOOR STAGE CONFIGURATION FAULT, Missing Outdoor Stage Configuration Fault Trane · DUPLICATE INDOOR STAGES CONFIGURATION FAULT, Duplicate Indoor Stages Configuration Fault Lennox · 10, Unknown device detected Lennox · 11, Missing device Lennox · 30, Low temperature protection Lennox · 31, Lost communication with device Lennox · 105, Wiring issue / communication problem Lennox · 110, Low AC line voltage Lennox · 112, No ground connection Lennox · 113, High AC line voltage Lennox · 400, OD compressor internal overload tripped Lennox · 401, OD compressor long run cycle (information) Lennox · 402, OD system pressure trip Lennox · 403, OD compressor short-cycling Lennox · 404, OD compressor rotor locked Lennox · 405, OD compressor open circuit Lennox · 406, OD compressor open start circuit Lennox · 407, OD compressor open run circuit Lennox · E1, Pressure Sensor Fault Lennox · E2, Outdoor Coil Sensor Fault Lennox · E3, Indoor Coil Sensor Fault Lennox · E6, iComfort Communication Fault Lennox · E8, High Discharge Temperature Lennox · E11, Ambient Sensor Fault Lennox · E231, High Pressure Lockout Lennox · E232, Low Pressure Lockout Lennox · E233, Compressor Over-Current Lockout Lennox · E244, Defrost Termination Fault Lennox · E290, ECM Motor Fault Lennox · 560, iComfort Wi-Fi Connection Lost Lennox · 263, High-Pressure Switch Open Lennox · 266, Low-Pressure Switch Open Lennox · 299, Compressor Phase Loss Goodman · Steady ON, Normal standby Goodman · Steady OFF, No power Goodman · Continuous rapid flash, Reversed polarity or grounding issue Goodman · Slow continuous flash, Normal heating operation Goodman · 1 Flash, Ignition failure / Flame failure Goodman · 2 Flashes, Pressure switch stuck closed Goodman · 3 Flashes, Pressure switch open / Draft blower fault Goodman · 4 Flashes, Open high limit switch Goodman · 5 Flashes, Flame sensed without call for heat Goodman · 6 Flashes, Rollout switch open Goodman · 7 Flashes, Low flame signal Goodman · 8 Flashes, Igniter circuit error Goodman · 9 Flashes, Reversed line polarity or grounding problem Goodman · 1, Fault Code 1 Goodman · 2, Fault Code 2 Goodman · 3, Fault Code 3 Goodman · 4, Fault Code 4 Goodman · 5, Fault Code 5 Goodman · Continuous Blink, Normal operation Goodman · E01, Ignition failure (Digital) Goodman · E02, Pressure switch fault (Digital) Goodman · E03, High-limit switch fault (Digital) Goodman · E05, Flame sensor fault (Digital) Goodman · Continuous flashing, Reversed polarity Goodman · E5, BLOWN FUSE Goodman · EE, INTERNAL FAULT Goodman · EF, AUXILIARY SWITCH OPEN Goodman · b0, NO ID AIRFLOW Goodman · b1, Blower Communication Error Goodman · b9, LOW ID AIRFLOW Goodman · d0, NO NET DATA Goodman · d1, INVALID DATA Goodman · E13, High pressure (critical) Goodman · E15, Low pressure (critical) Goodman · E17, Compressor fail Goodman · E19, PCB or fan fail Goodman · E22, High Discharge Temperature Goodman · E23, Discharge Temperature Sensor Fail Goodman · E24, HPS Open Goodman · E25, AIR SENSOR FLT Goodman · E26, PRESSURE SENSOR Goodman · E31, HI LEAK CURRENT Goodman · E34, CURRENT SPIKE Goodman · E35, HIGH CURRENT Amana · E11, System Verification Test Required Amana · E13, High Pressure (Minor) Amana · E15, Low Pressure (Critical) Amana · E17, Compressor Failure Amana · E19, Control Board or Fan Failure Amana · E21, EEV Control Failure Amana · E22, High Discharge Temperature Amana · E23, Discharge Temperature Sensor Failure Amana · E24, High Pressure Switch Open Amana · E26, Pressure Sensor Malfunction Amana · E28, Outdoor Coil Temperature Sensor Failure Amana · E29, Liquid Line Temperature Sensor Failure Amana · E31, High Leakage Current Rheem · 1 flash, System lockout Rheem · 2 flashes, High-pressure switch open Rheem · 3 flashes, Low-pressure switch open Rheem · 4 flashes, Compressor overload Rheem · 5 flashes, Condenser fan motor fault Rheem · 6 flashes, Defrost control fault Rheem · E1, Loss of communication Rheem · E5, Low refrigerant alert Rheem · E6, High discharge temperature Rheem · P1, High-pressure cutout Rheem · P3, Low-pressure cutout Rheem · F1, Indoor unit coil temperature sensor fault Rheem · No flash / off, No power Rheem · T905_O, Inverter Fault – DC Bus Undervoltage Rheem · T904_O, Inverter Fault – DC Bus Overvoltage Rheem · A906_O, Inverter Fault – AC Input Overvoltage Rheem · A907_O, Inverter Fault – AC Input Undervoltage Rheem · T901_O, Inverter Fault – Compressor Overcurrent Rheem · T902_O, Inverter Fault – Envelope Protection Rheem · 0, Standby Rheem · H, Gas Heat ON Rheem · C, Compressor ON Rheem · F, Continuous Fan ON Rheem · 10, One-Hour Lockout Rheem · 11, Failed Ignition Rheem · 12, Low Flame Sense Rheem · 13, Flame Lost Rheem · 14, Unexpected Flame Rheem · 20, Twinning Fault Rheem · 22, Main Limit Open Rheem · 26, Line and Neutral Reversed Rheem · 33, MRLC (Manual Reset Limit Control) Open Rheem · 45, Low-Pressure Switch Open Rheem · Code E1, Loss of Communication Rheem · Code E5, Low Refrigerant Alert Rheem · Code E6, High Discharge Temperature Rheem · Code P1, High-Pressure Cutout Rheem · Code P3, Low-Pressure Cutout Rheem · Code F1, Indoor Unit Coil Temperature Sensor Fault Rheem · Continuous flash, Normal Operation Rheem · 55, Pressure switch stuck closed Rheem · 57, Pressure switch stuck open Rheem · 61, Blower fault Rheem · 93, Internal control fault Rheem · 1 flash (STATUS LED), Ignition failure Rheem · 2 flashes (STATUS LED), Pressure switch stuck open Rheem · 3 flashes (STATUS LED), Limit switch open Rheem · 4 flashes (STATUS LED), Pressure switch stuck closed Rheem · 5 flashes (STATUS LED), Twinning fault Rheem · 6 flashes (STATUS LED), Line and neutral reversed Rheem · FLAME LED, OFF, No flame detected Rheem · FLAME LED, rapid blink, Unexpected flame Rheem · FLAME LED, slow blink, Marginal flame sense Rheem · FLAME LED, steady ON, Normal flame detected Rheem · POWER LED, OFF, No 24 VAC power Rheem · POWER LED, ON, Control is powered York · FC 2, Anti-short-cycle delay (ASCD) active York · FC 3, High-pressure switch trip / lockout, stage 1 York · FC 4, High-pressure switch trip / lockout, stage 2 York · FC 5, Low-pressure switch trip / lockout, stage 1 York · FC 6, Low-pressure switch trip / lockout, stage 2 York · FC 7, Freeze-stat trip, stage 1 York · FC 8, Freeze-stat trip, stage 2 York · FC 9, Ignition control lockout or heating failure York · FC 10, Compressor lockout, low-ambient switch closed York · Steady On LED, Defective Board Fault York · LED not lit, Board Power Loss York · FC 11, Economizer Lockout York · FC 12, Fan Overload Lockout York · FC 13, Low Voltage Lockout York · FC 14, EPROM Failure York · 1 Flash, Normal Standby York · 2 Flashes, Normal Run York · 3 Flashes, Pressure Switch Fault York · 4 Flashes, Open Thermal Limit York · 5 Flashes, Control Voltage Fault York · 6 Flashes, Compressor Start Lockout York · 7 Flashes, Outdoor Sensor Fault York · E1, Simplicity Thermostat Comm Loss York · E9, Compressor Over-Current Bryant · 16, System communications failure Bryant · 25, Invalid model plug Bryant · 31, High pressure switch open Bryant · 32, Low pressure switch open Bryant · 45, Control fault Bryant · 46, Brown out (230V) Bryant · 47, No 230V at unit Bryant · 53, Outdoor air temperature sensor fault Bryant · 55, Outdoor coil sensor fault Bryant · 56, Thermistors out of range Bryant · 71, Low stage thermal cutout Bryant · 72, High stage thermal cutout Bryant · 73, Contactor shorted Bryant · 74, No 230V at compressor Bryant · 75, Low stage did not start Bryant · 76, Low stage did not start 3 times Bryant · 77, High stage did not start Bryant · 78, High stage did not start 3 times Bryant · 81, Low stage thermal lockout Bryant · 82, High stage thermal lockout Bryant · 83, Low-pressure lockout Bryant · 84, High-pressure lockout Bryant · 85, Low contactor open Bryant · 87, High contactor open Bryant · 178, Indoor unit communication fault Bryant · 179, Outdoor unit communication fault Heil · 13, Limit Device Lockout Heil · 14, Ignition Lockout Heil · 21, Gas Valve Circuit Fault Heil · 22, Abnormal Flame Sense Heil · 31, Pressure Switch Stuck Open Heil · 32, Pressure Switch Stuck Closed Heil · 34, Ignition Proving Fault Heil · 41, Blower Motor Fault Heil · 42, Inducer Motor Fault Heil · 45, Control Board Fault Heil · E1, ION Comm Loss, Outdoor Unit Heil · E2, ION Comm Loss, Air Handler Mitsubishi · 403, Communication Fault Mitsubishi · 900, Lossnay Test Run Mitsubishi · 1102, High Discharge Temperature Mitsubishi · 1111, Low Pressure/Temperature Fault Mitsubishi · 1202, Preliminary Discharge Temp Fault Mitsubishi · 1301, Low Pressure Start Fault Mitsubishi · 1302, High Pressure Fault Mitsubishi · 1500, System Overcharge Mitsubishi · 1505, Suction Pressure Vacuum Mitsubishi · 2500, Water Flow Fault Mitsubishi · 2502, Drain Level Fault (Temp Sensor) Mitsubishi · 4102, Open Phase Fault Mitsubishi · 4116, Fan Motor Abnormal Mitsubishi · 4220, Low Inverter BUS Voltage Mitsubishi · 4230, Heat Sink Overheat Mitsubishi · 4250, Compressor Lock / IPM Fault Mitsubishi · P1, Intake sensor error Mitsubishi · P4, Drain sensor error Mitsubishi · P5, Drain pump error Mitsubishi · P6, Freezing/Overheating safeguard Mitsubishi · E6, Indoor/Outdoor communication error Mitsubishi · UP, Compressor overcurrent interruption Mitsubishi · U2, Abnormal discharging temperature Mitsubishi · U1, Abnormal high pressure Mitsubishi · EA, Mis-wiring error Mitsubishi · F1, Reverse phase detection Mitsubishi · Fb, Indoor control system error Mitsubishi · U5, Heat sink temperature error Mitsubishi · 0403, Serial communication error Mitsubishi · 0900, Test run Mitsubishi · 2600, Water leak Mitsubishi · 4230/4260, Heatsink overheat protection activated Mitsubishi · 5101, Temperature sensor fault Mitsubishi · 6600, Address overlap Mitsubishi · UE, High pressure error Mitsubishi · UL, Abnormal low pressure Mitsubishi · E1, Remote Controller Fault Mitsubishi · 5201, Suction Pipe Thermistor Fault Mitsubishi · E7, Outdoor to Outdoor Communication Loss Mitsubishi · E0, Remote Controller Communication Error Mitsubishi · UA, High Pressure Trip Mitsubishi · P9, M-NET Communication Error Mitsubishi · L3, Charge Abnormality Mitsubishi · U3, Short Cycle Abnormality Mitsubishi · A1, Indoor PCB Abnormality Mitsubishi · F6, Heat Exchanger Overheat Mitsubishi · P2, Pipe sensor error (Liquid) Mitsubishi · P3, Signal transmission error Mitsubishi · P7, System error (Address) Mitsubishi · P8, Outdoor unit abnormality Mitsubishi · PA, Forced compressor error Mitsubishi · E2, Remote controller board error Mitsubishi · E3, Remote control transmission error Mitsubishi · E4, Remote control signal receiving error Mitsubishi · E5, Remote control transmitting error Mitsubishi · E8, Outdoor unit transmission error Mitsubishi · E9, Outdoor unit transmission error Mitsubishi · Eb, Mis-wiring / Disconnection Mitsubishi · EC, Start-up time over Mitsubishi · Ed, Serial transmission error Mitsubishi · EE, Indoor/Outdoor communication error Mitsubishi · EF, M-NET transmission error Mitsubishi · F2, L3 open phase detection Mitsubishi · F3, 63L connector open Mitsubishi · F4, 49C connector open Mitsubishi · F7, Reverse phase detection circuit fault Mitsubishi · F8, Input circuit fault Mitsubishi · F9, Multiple connector open Mitsubishi · FA, L2-phase open or 51CM open Mitsubishi · U4, Outdoor thermistor short/open Mitsubishi · U6, Compressor overcurrent/Power module error Mitsubishi · U7, Abnormality of super heat Mitsubishi · U8, Outdoor fan safeguard stop Mitsubishi · U9, Voltage abnormality Mitsubishi · Ud, Overheat protection Mitsubishi · UF, Compressor locked Mitsubishi · UH, Current sensor error Mitsubishi · LED LD1, Reverse phase detection (Outdoor) Mitsubishi · LED LD2, Open phase detect (Outdoor) Mitsubishi · LED LD3, Pipe sensor short/open (Outdoor) Daikin · A0, External protection device activated Daikin · A1, Indoor PCB malfunction Daikin · A3, Drain water level abnormal Daikin · A5, High pressure or freeze-up protection Daikin · A6, Indoor fan motor fault Daikin · A7, Swing flap motor fault Daikin · A9, Electronic expansion valve fault Daikin · AH, Streamer / air filter fault Daikin · C4, Indoor heat exchanger thermistor fault Daikin · A4, Malfunction of freezing protection Daikin · A8, Malfunction of power supply Daikin · AA, Heater overheat Daikin · AF, Malfunction of humidifier system Daikin · AJ, Malfunction of capacity setting Daikin · C1, Transmission failure Daikin · C5, Gas pipe thermistor fault Daikin · C6, Fan motor driver malfunction Daikin · C7, Front panel motor fault Daikin · C9, Suction air thermistor fault Daikin · CA, Discharge air thermistor fault Daikin · CC, Humidity sensor system fault Daikin · CJ, Remote controller sensor fault Daikin · E0, Protection devices actuated Daikin · E1, Outdoor unit PCB defect Daikin · E3, High pressure switch actuation Daikin · E4, Low pressure switch actuation Daikin · E5, Compressor motor overheat or lock Daikin · E6, Standard compressor overcurrent/lock Daikin · E7, Outdoor fan motor malfunction Daikin · E8, Inverter compressor overcurrent Daikin · E9, Electronic expansion valve coil fault Daikin · 00, Normal Daikin · UA, Indoor-Outdoor Unit Combination Fault Daikin · U0, Refrigerant Shortage Daikin · U2, Voltage Fault Daikin · U4, Transmission Failure Daikin · F3, High Temperature Discharge Pipe Control Daikin · F6, High Pressure Control Daikin · H0, Sensor Fault Daikin · H6, Faulty Position Detection Sensor Daikin · H8, DC Current Sensor Fault Daikin · H9, Faulty Suction Air Temperature Sensor (Outdoor) Daikin · J3, Faulty Discharge Pipe Temperature Sensor Daikin · J6, Faulty Heat Exchanger Temperature Sensor (Outdoor) Daikin · L3, Electrical Parts Heat Fault Daikin · L4, High Temperature at Inverter Circuit Heatsink Daikin · L5, Output Overcurrent Daikin · P4, Faulty Inverter Circuit Heatsink Temperature Sensor Daikin · AO, External Protection Device Error Daikin · C3, Drain Thermistor Malfunction Daikin · CE, Radiant Heat Sensor Malfunction Daikin · EA, Four-Way Valve Defective Daikin · FC, Low Pressure Drop Daikin · H3, High Pressure Switch Defect Daikin · H4, Low Pressure Switch Defect Daikin · H7, Fan Motor Position Detection Sensor Error Daikin · J1, Pressure Sensor Malfunction Daikin · J2, Current Sensor Malfunction Daikin · J4, Low Pressure Saturation Thermistor Malfunction Daikin · J5, Suction Pipe Thermistor Malfunction Daikin · J7, Heat Exchanger Liquid Thermistor Malfunction Daikin · J8, Liquid Pipe Thermistor Malfunction (Outdoor) Daikin · J9, Gas Pipe Thermistor Malfunction (Outdoor) Daikin · JA, Discharge Pipe Pressure Sensor Malfunction Daikin · JC, Suction Pipe Pressure Sensor Malfunction Daikin · JH, Oil Temperature Sensor Malfunction Daikin · L0, Inverter Malfunction Daikin · L6, Compressor Motor Grounding/Short Circuit Daikin · L7, Total Input Overcurrent Daikin · L8, Compressor Overload Daikin · L9, Compressor Lock Daikin · LA, Power Unit Malfunction Daikin · LC, Transmission Between Inverter and Outdoor PCB Daikin · P1, Inverter Over Ripple Daikin · P3, Thermistor Abnormality Daikin · PJ, Failure of Capacity Set Resistor Daikin · U1, Negative Phase / Open Phase Daikin · U3, Wiring Check Operation Not Executed Daikin · U5, Transmission to Remote Controller Daikin · U6, Malfunction Transmission Outdoor to BP Unit Daikin · U7, Transmission Between Outdoor Units Daikin · U8, Transmission Between Master and Slave R/C Daikin · U9, Transmission Error Between Indoor to Outdoor Daikin · UC, Address Duplication of Central Controllers Daikin · UE, Transmission Error Between Indoor and Central Daikin · UF, Refrigeration System Not Set/Wiring - Piping LG · 01, Indoor Unit Return Air Sensor Fault LG · 02, Indoor Pipe or Outdoor Sensor Assy Fault LG · 03, Remote Controller Comms Error LG · 04, Heat Sink Sensor or Condensate Pump Error LG · 05, Communication Error LG · 06, Indoor Unit Coil Sensor Fault LG · 07, Mode Mismatch or Compressor Over Current LG · 08, Indoor BLDC Fan Problem LG · 09, Outdoor Fan or Indoor EEPROM Error LG · 10, Compressor Discharge Sensor Fault LG · 11, Indoor Unit Not Connected LG · 12, EEPROM Sum Check Error LG · 13, PSC Reactor Error LG · 14, Compressor Phase Current Error LG · 21, Inverter Compressor Run Current High LG · 23, Inverter DC Voltage Low LG · CH01, Indoor Return Air Thermistor Fault LG · CH02, Indoor Pipe Temperature Sensor Error LG · CH05, Outdoor Unit Pipe Temperature Sensor Failure LG · CH07, Outdoor Ambient Temperature Sensor Fault LG · 22, Inverter Overcurrent LG · 32, High Discharge Temperature LG · 40, CT Sensor Error LG · 51, Indoor Communication Loss LG · 53, Master-Slave Communication Failure LG · C6, High Compressor Current LG · CH 02, Indoor Abnormality LG · CH 05, Comm Error (IN/OUT) LG · CH 10, Fan Motor Abnormality LG · CH 21, Compressor Overcurrent LG · CH 22, Current Sensor Error LG · CH 23, DC Link Low Voltage LG · CH 26, Compressor Overheating LG · CH 27, Abnormal Discharge Temp LG · 24, High or Low Pressure Trip LG · 25, Input Voltage Error LG · 26, Inverter Compressor Seized LG · 27, Inverter Current Irregularity LG · 28, Inverter DC Voltage High LG · 33, Standard Compressor Discharge Temp Rise LG · 34, Excessive High Pressure Rise LG · 35, Excessive Low Pressure Drop LG · Co, Auto Clean LG · LO, Test Operation LG · PO, Jet Mode LG · C1, Room Temperature Sensor Fault LG · AI, Auto Function LG · CH 01, Indoor Unit Ambient Sensor Malfunction LG · CH 03, Remote Control Communication Error LG · CH 04, Drainage Pump / Heat Sink Sensor Error LG · CH 06, Indoor Unit Pipe Outlet Sensor Malfunction LG · CH 07, Mode Mismatch / Compressor Overcurrent LG · CH 09, Indoor unit EEPROM / Outdoor fan problem LG · CH 11, Indoor unit communication error LG · CH 24, Compressor Output Head Too High LG · CH 25, Input Voltage High or Low LG · CH 43, High Pressure Sensor Failure LG · CH 44, Outdoor Unit Ambient Sensor Faulty LG · CH 50, Outdoor Unit Phase Connection Error LG · CH 51, Capacity Excess LG · CH 53, Indoor-Outdoor Main PCB Communication Error LG · CH 60, Inverter PCB EEPROM Error LG · CH 62, Heat Sink Sensor Overheat LG · CH 67, Outdoor Unit Fan Locked LG · CH 242, Network Failure LG · 61, Wired remote controller communication error Fujitsu · 00, ID to RC Comms Fail Fujitsu · 01, ID to OD Comms Fail Fujitsu · 02, ID Air Sensor Open Fujitsu · 09, Drain Problem Fujitsu · 0C, Discharge Sensor Fail Fujitsu · 11, OD PCB Fail Fujitsu · 12, ID Fan Fail Fujitsu · 17, IPM Error Fujitsu · 1A, Compressor Failure Fujitsu · 2C, Four-way Valve Abnormal Fujitsu · R2-G6, Float switch operated Fujitsu · R5-G6, Outdoor Fan Failure Fujitsu · R7-G2, High Discharge Temperature Fujitsu · 15, Automatic air flow adjustment error Fujitsu · 18, External communication error Fujitsu · 23, Combination error Fujitsu · 26, Address setting error in wired remote control system Fujitsu · 29, Connection unit number error Fujitsu · 32, Indoor unit PCB model information error Fujitsu · 33, Indoor unit motor electricity consumption detection error Fujitsu · 35, Manual auto switch error Fujitsu · 39, Indoor fan motor power supply error Fujitsu · 3A, Indoor unit communication circuit (wired remote control) error Fujitsu · E0:00-E1:00, Communication Breakdown Fujitsu · E2:00-E5:00, Indoor Sensor Glitch Fujitsu · E6:00-ED:00, Outdoor Sensor Glitch Fujitsu · EE:00-EF:00, Refrigerant or Pressure Problem Fujitsu · 1 red flash + 1 green, Serial Communication Failure Fujitsu · 2 red + rapid green, Outdoor Fan Trouble Fujitsu · Steady red + blinking green, Freeze Protection Active Fujitsu · Orange Timer LED blinks twice every 12 seconds, Circuit Voltage Verification Required Fujitsu · E1, Communication Error Fujitsu · 53, Drainage Error Fujitsu · 97, Outdoor Unit Fan Motor Error Fujitsu · A1, Discharge Temp High Fujitsu · 21, Wiring/Piping Error Fujitsu · 22, Indoor Capacity Error Fujitsu · 41, Indoor Room Thermistor Fujitsu · 5U.1, Indoor Unit Error Fujitsu · 51, Indoor Fan Motor Error Fujitsu · 63, Inverter Error Fujitsu · 64, A.F. Voltage Error Fujitsu · 6A, Display PCB Communication Fujitsu · 71, Discharge Thermistor Error Fujitsu · 72, Compressor Thermistor Error Fujitsu · 73, Heat Exchanger Liquid Thermistor Fujitsu · 24, Indoor Unit Number Error Fujitsu · 42, Indoor Heat Exchanger Thermistor Error Fujitsu · 57, Damper Error Fujitsu · 58, Intake Grille Error Fujitsu · 62, Outdoor Unit Info Error Fujitsu · 74, Outdoor Unit Fault Fujitsu · E:10, Indoor to Outdoor Communication Loss Fujitsu · E:11, Outdoor to Outdoor Communication Loss Fujitsu · E:12, Remote Controller Communication Error Fujitsu · E:21, High Pressure Trip Fujitsu · E:23, Low Pressure / Refrigerant Shortage Fujitsu · E:22, Discharge Temp Too High Fujitsu · E:32, Float Switch / Drain Overflow Fujitsu · E:31, Condensate Pump Fault Fujitsu · E:E1, Indoor-Outdoor Comm Error Fujitsu · E:E2, Address Conflict Fujitsu · E:E5, Inter-Indoor Comm Error Fujitsu · E:EE, Outdoor Power Supply Error Fujitsu · U:01, Compressor Abnormality Fujitsu · U:11, High Discharge Temp Fujitsu · U:30, High Pressure Switch Trip Fujitsu · U:48, Discharge Thermistor Fault Fujitsu · EE:00 or EF:00, Pressure/Refrigerant Alert Fujitsu · Economy light fast blinks, Secondary Diagnostic Alert Fujitsu · 2 Orange Timer blinks (every 12 sec), Circuit Voltage Verification Error Fujitsu · Continuous yellow LED flashes, Power Indicator Fault Samsung · E101, Outdoor Unit Communication Error Samsung · E102, Outdoor to Indoor Communication Error Samsung · E103, Indoor Panel Communication Error Samsung · E104, Internal Indoor Communication Error Samsung · E108, Duplicate Address Error Samsung · E109, Incomplete Address Error Samsung · E121, Room Temperature Sensor Error Samsung · E122, Indoor Evaporator In Sensor Error Samsung · E123, Indoor Evaporator Out Sensor Error Samsung · E124, Indoor to Outdoor Communication Error Samsung · E130, Dual Evaporator Sensor Breakaway Samsung · E131, Electronic Heater Sensor 1 Error Samsung · E137, VOC Sensor Error Samsung · E140, Indoor Dust Sensor Error Samsung · E151, EEV Open Error Samsung · E153, Indoor Float Switch Error Samsung · E154, Indoor Fan Error Samsung · E161, Mixed Operation Error Samsung · E162, Outdoor EEPROM Error Samsung · 101, Indoor Communication Error Samsung · 102, Outdoor to Indoor Communication Error Samsung · 108, Duplicate Address Error Samsung · 109, Incomplete Indoor Address Error Samsung · 121, Room Temperature Sensor Error Samsung · 122, Evaporator Inlet Sensor Error Samsung · 139, ERV CO2 Sensor Error Samsung · 151, Expansion Valve Open Error Samsung · 154, Indoor Fan Error Samsung · 161, Mixed Operation Error Samsung · 162, Outdoor Unit EEPROM Error Samsung · 185, Power Line Communication Cross Error Samsung · 192, Indoor Unit Cover Safety Error Samsung · 198, Thermal Fuse Disconnection Error Samsung · 201, Indoor Unit Quantity Mismatch Samsung · 203, Main-Sub Outdoor Communication Error Samsung · E201, Communication Tracking Error Samsung · E221, Outdoor Ambient Temperature Sensor Error Samsung · E416, Discharge Temperature Over-High Samsung · E458, Outdoor Fan Motor Error Samsung · E461, Compressor Startup Failure Samsung · E464, IPM Overcurrent Error Samsung · E554, Refrigerant Leak Detection Samsung · CF, Filter Cleaning Reminder Samsung · E202, Indoor Address Conflict Samsung · E440, Compressor Cycling Protection Samsung · E441, Sustained Compressor Protection Samsung · 202, System Communication Error Samsung · 210, MCU Communication Error Samsung · 221, Outdoor Temperature Sensor Error Samsung · 251, Discharge Temperature Sensor Error Samsung · 267, High Pressure Sensor Breakaway Panasonic · H11, Indoor / Outdoor abnormal communication Panasonic · H12, Other Power Error Between Outdoor Unit and Indoor Unit Panasonic · H14, Room Temperature Sensor Error Panasonic · H15, Compressor Discharge Temperature Sensor Error Panasonic · H16, Compressor Load Current is Too Low Panasonic · H17, Outdoor Suction Pipe Temperature Sensor Error Panasonic · H19, Motor mechanism of indoor fan locked Panasonic · H21, Drainage blocked or float sensor defective Panasonic · H23, Indoor heat exchanger temperature sensor abnormality Panasonic · H25, Defective ionization unit or internal board Panasonic · H27, Outdoor intake air temperature sensor abnormality Panasonic · H28, Outdoor heat exchanger temperature sensor abnormality Panasonic · H30, Outdoor discharge air temperature sensor abnormality Panasonic · H33, Indoor / Outdoor wrong connection Panasonic · H34, Outdoor heat sink temperature sensor abnormality Panasonic · H36, Outdoor unit gas tube temperature sensor error Panasonic · H37, Outdoor unit liquid tube temperature sensor short-circuited Panasonic · H38, Indoor/Outdoor Brand Mismatch Panasonic · H39, Abnormal Indoor Operating Unit Panasonic · H41, Incorrect Wiring and Freon Wiring Panasonic · H50, Defective Fan Motor or Board Panasonic · H64, High Pressure Sensor Malfunction Panasonic · H94, Compressor Discharge Temperature Sensor Malfunction Panasonic · H97, Faulty Outdoor Fan Motor Panasonic · H98, Total Current Consumption Protection Panasonic · H99, DC Protection System Error Panasonic · F11, 4-Way Valve Operation Abnormality Panasonic · F17, Freezing of the Indoor Unit Panasonic · F90, Open Circuit of Compressor Windings Panasonic · F91, Refrigeration Circuit Abnormality Panasonic · F93, Compressor Speed Error Panasonic · F94, Overpressure Protection Panasonic · F95, Outdoor Heat Exchanger Overheating Panasonic · F96, Power Module Overheating Panasonic · F97, High Compressor Discharge Temperature Panasonic · F98, Total Current Consumption Protection Panasonic · F99, DC Protection System Error Panasonic · S01, Room temperature sensor failure Panasonic · S02, Indoor coil sensor failure Panasonic · S03, Humidity sensor failure Panasonic · S04, Comp. temperature sensor failure Panasonic · S05, Outdoor coil sensor failure Panasonic · S06, Outdoor air sensor failure Panasonic · S07, Outdoor current sensor failure Panasonic · E01, Indoor/outdoor communication failure Panasonic · E02, HIC circuit failure Panasonic · E03, Outdoor unit OTP rom failure Panasonic · E04, Peak current cut off Panasonic · E05, PAM or Active circuit failure Panasonic · E06, High compressor discharge temperature Panasonic · E07, Indoor fan operating failure Panasonic · E08, Way valve switching failure (RV) Panasonic · E09, No refrigerant protection Panasonic · E10, DC compressor drive circuit failure Panasonic · E11, Outdoor fan operating failure Panasonic · E12, Error in outdoor unit Panasonic · E13, Freeze prevention activated Panasonic · E14, Main unit duplication Panasonic · E15, Automatic address alarm (capacity too low) Panasonic · E16, Automatic address alarm (capacity too high) Panasonic · E20, No indoor units connected Panasonic · F04, Compressor discharge temperature sensor (TD) trouble Panasonic · F06, Inlet temperature sensor (C1) trouble Panasonic · F07, Intermediate temperature (C2) trouble AAON · AL001, No Compressor Response AAON · AL002, No Heat Response AAON · AL010, High Supply Air Temp AAON · AL020, Low Supply Air Temp AAON · AL030, High Refrigerant Pressure AAON · AL031, Low Refrigerant Pressure AAON · AL040, Compressor Thermal Overload AAON · AL050, OE332 Comm Fault AAON · AL051, OE332 Memory Fault AAON · AL060, Dirty Filter Alarm AAON · AL070, Economizer Fault AAON · AL080, Smoke Detector Alarm
Or search by code, name, or symptom Browsing all 841 codes · page 1 of 17 Prev Next
Carrier · Infinity / ComfortLink II / Greenspeed
44 , Motor Communication Fault
Shutdown The system has lost communication between the control board and the indoor blower motor.
Likely Causes
Failed motor serial interface Loose communication wire Faulty indoor control board First Checks
Check wiring harness between motor and control board Verify 24VAC and high voltage power to the motor Inspect connectors for corrosion or loose pins Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
41 , Blower Motor Fault
Shutdown The system has detected a general failure or operation error within the indoor blower motor.
Likely Causes
Seized motor bearings Internal motor controller failure Blower wheel imbalance First Checks
Check for obstructions in the blower wheel Verify motor power supply Ensure motor shaft rotates freely Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
15 , Blower Motor Lockout
Shutdown The furnace control has locked out blower operation due to a persistent motor fault.
Likely Causes
Repeated motor start failures Overheated blower motor Faulty control board relay First Checks
Power cycle the furnace to attempt a reset Check motor wiring and ground Check for any physical blockages in the fan housing Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
37 , Heater Output Sensed On
Warning The heater output was detected as active even though the control board had not energized it.
Likely Causes
Welded sequencer or contactor Short circuit in heater control wiring Failed indoor control board First Checks
Check for shorted heating element contactors Inspect control board for stuck relays Verify voltage at heater terminals while idle Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
13 , Limit Circuit Lockout
Warning The furnace limit switch has opened and remained open, leading to an operation lockout.
Likely Causes
Restricted airflow Defective limit switch Over-fired furnace First Checks
Check for dirty air filters Inspect all supply registers and return grilles for blockages Verify blower motor speed and operation Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
14 , Ignition Lockout
Warning The furnace failed to ignite the gas burner or prove the flame after several attempts.
Likely Causes
Dirty flame sensor Faulty igniter Low gas pressure Defective gas valve First Checks
Verify gas supply valve is open Check condition of the igniter Inspect the flame sensor for soot or oxidation Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
21 , Gas Heating Lockout
Warning The system has locked out gas heating operation due to repeated malfunctions.
Likely Causes
Repeated ignition failures Continuous limit circuit trips Gas valve circuit malfunction First Checks
Check gas supply and manifold pressure Verify proper venting and combustion air Review previous fault codes in history Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
22 , Abnormal Flame Proving Signal
Warning A flame signal was detected by the control board while the gas valve was supposed to be closed.
Likely Causes
Leaking gas valve Faulty flame sensor Control board sensing error First Checks
Check for a leaking gas valve Inspect flame sensor wiring for shorts to ground Ensure the burner is not actually lit Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
23 , Pressure Switch Did Not Open
Warning The inducer pressure switch stayed in the closed position when it was expected to be open at start-up.
Likely Causes
Stuck pressure switch Miswired control circuit Obstruction in the pressure switch tubing First Checks
Check for a stuck or shorted pressure switch Verify wiring to the pressure switch Check for debris holding the switch closed Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
24 , Secondary Voltage Fuse Open
Warning The 24-volt fuse on the furnace control board has blown, indicating a low-voltage short.
Likely Causes
Shorted contactor coil Pinched thermostat wire Faulty accessory component First Checks
Inspect low voltage wiring for shorts to ground Check contactor coils for shorts Verify thermostat wiring integrity Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
33 , Limit Circuit Fault
Warning The limit circuit has opened, and the system is operating in high heat only as a result.
Likely Causes
Airflow restriction Faulty limit switch High static pressure First Checks
Check for dirty air filters Verify all dampers are open Check blower motor RPM and static pressure Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
45 , Control Circuitry Lockout
Warning An internal software or hardware failure has occurred within the furnace control board.
Likely Causes
Internal board component failure Electrical interference/noise Memory failure on board First Checks
Reset power to the furnace control Check for proper grounding Verify secondary voltage is within range Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
VC VOLTAGE AT STANDBY , Voltage at Standby
Warning Unexpected voltage was detected on the compressor circuit while the unit was in standby mode.
Likely Causes
Stuck or welded contactor Shorted wiring Control board relay failure First Checks
Check contactor for welded contacts Inspect outdoor unit wiring Verify control signals from the indoor unit Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
HI CAPACITY COMPRESSOR LOCKOUT , High Capacity Compressor Lockout
Warning The outdoor unit has locked out high-capacity operation due to a performance or electrical issue.
Likely Causes
Low refrigerant charge Faulty compressor start components Internal compressor thermal overload First Checks
Check compressor capacitor Verify refrigerant levels Check compressor winding resistance Source: Carrier Infinity/Evolution Troubleshooting Guide Rev2 (gpsinformation.info)
Carrier · Infinity / ComfortLink II / Greenspeed
AF , Airflow Restrictions Detected
Warning The system has detected that the airflow is restricted, which can lead to inefficient operation.
Likely Causes
Dirty air filters Closed supply vents Blocked return air duct First Checks
Check air filters for dirt Inspect all vents for closure Check ductwork for obstructions Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
HP , High-Pressure Lockout
Lockout, Manual Reset The system has shut down to protect components due to excessively high refrigerant pressure.
Likely Causes
Dirty outdoor coils Faulty outdoor fan motor Debris blocking airflow in the outdoor unit First Checks
Check outdoor unit for dirt and debris Verify the outdoor fan motor is running Check for coil obstructions Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
LP , Low-Pressure Lockout
Lockout, Manual Reset The system has shut down because the refrigerant pressure has dropped below the safe operating threshold.
Likely Causes
Low refrigerant charge Refrigerant leak in the lines or coils First Checks
Check refrigerant levels Inspect system for visible leaks Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
OP , Outdoor Temperature Sensor Fault
Warning The system is unable to read the outdoor temperature correctly due to a sensor malfunction.
Likely Causes
Faulty outdoor temperature sensor Damaged sensor wiring First Checks
Inspect the outdoor temperature sensor Check sensor wiring for damage or loose connections Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
101 , Communication Fault
Shutdown There is a failure in communication between the indoor and outdoor control boards.
Likely Causes
Loose wiring connections Faulty communication module Interrupted control signal First Checks
Check all wiring connections between units Reset the system by cycling power for 10 minutes Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
181 , Low System Charge
Warning The system has detected a low refrigerant level which is impacting heating or cooling performance.
Likely Causes
Refrigerant leak Undercharged system from installation First Checks
Look for visible oil or refrigerant leaks Check refrigerant levels with gauges Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
323 , Outdoor Fan Fault
Shutdown The system has detected a failure or malfunction with the outdoor fan motor operation.
Likely Causes
Faulty fan motor Failed fan capacitor Motor overheating First Checks
Inspect the outdoor fan for physical obstructions Check if the fan motor is overheating Source: MachineAnswered, Carrier Infinity Fault Codes Guide
Carrier · Infinity / ComfortLink II / Greenspeed
Constant On , No Demand / Standby
Information The system is powered and operational but currently has no active demand for heating or cooling.
Likely Causes
Normal operation Thermostat at setpoint No call for service First Checks
Check thermostat settings Verify communication with the indoor unit Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
1 , 1st Stage Compressor
Information The outdoor unit is currently operating in its first stage of compressor capacity.
Likely Causes
Normal operation for low-demand cooling or heating Sensor wiring open, shorted, or intermittent Sensor drifted out of spec or failed Loose or corroded connector at sensor or control board First Checks
Verify compressor operation Observe system performance Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
2 , 2nd Stage Compressor
Information The outdoor unit is currently operating in its second (high) stage of compressor capacity.
Likely Causes
Normal operation for high-demand cooling or heating Sensor wiring open, shorted, or intermittent Sensor drifted out of spec or failed Loose or corroded connector at sensor or control board First Checks
Verify compressor operation Observe system performance Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
16 , System Communication Failure
Shutdown The communication link between the outdoor control board and the rest of the system is broken.
Likely Causes
Loose wire connections Broken or shorted communication wires Electrical interference Failed control board First Checks
Check ABCD wiring connections Inspect for damaged communication wires Reset power to the entire system Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
25 , Invalid Model Plug
Shutdown The control board has detected a missing or incorrect model plug for this unit.
Likely Causes
Missing model plug Model plug not fully inserted Incorrect model plug installed First Checks
Verify model plug is seated correctly Check that the model plug matches the unit model Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
31 , Hi Pressure Switch Trip
Shutdown The high pressure switch has opened due to excessive refrigerant pressure.
Likely Causes
Dirty outdoor coil Outdoor fan motor failure Refrigerant overcharge Non-condensables in system First Checks
Check outdoor coil for debris Verify outdoor fan is operating Check for closed service valves Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
32 , Low Pressure or Discharge Temp Switch Trip
Shutdown The system has tripped due to low refrigerant pressure or high compressor discharge temperature.
Likely Causes
Refrigerant leak Dirty indoor filter Faulty indoor blower motor Restricted expansion valve First Checks
Check refrigerant charge levels Inspect indoor air filter and coil Check for indoor blower operation Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
46 , Low Line Voltage (Brown Out)
Shutdown The incoming line voltage is below the minimum threshold for safe unit operation.
Likely Causes
Utility company brownout Undersized power supply wiring Loose electrical connections First Checks
Measure line voltage at the disconnect Check for loose power connections Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
47 , No Power Present at O/D Unit
Shutdown The control board is not detecting high-voltage power at the outdoor unit.
Likely Causes
Tripped circuit breaker Blown fuses Broken power wire First Checks
Check main circuit breaker Check outdoor disconnect fuses Verify wiring from disconnect to unit Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
53 , Outdoor Temp Sensor Failure
Warning The sensor measuring outdoor ambient temperature is malfunctioning.
Likely Causes
Faulty temperature sensor Disconnected or cut sensor wire Corroded connector First Checks
Check sensor wiring and plug Measure sensor resistance (ohms) Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
55 , Outdoor Coil Sensor Failure
Warning The sensor measuring outdoor coil temperature is malfunctioning.
Likely Causes
Faulty coil sensor Broken sensor wire Moisture in sensor connector First Checks
Check sensor wiring and plug Measure sensor resistance (ohms) Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
56 , Thermistors (Outdoor & Coil) Out of Range
Warning The outdoor and coil sensors are reporting values that are inconsistent with expected operating ranges.
Likely Causes
Faulty sensors Extreme environmental conditions Wiring short across sensor circuits First Checks
Inspect both sensor connections Verify sensors are mounted correctly Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
71 , Low Stage Thermal Cutout
Shutdown The compressor thermal protector has opened during low-stage operation.
Likely Causes
Low refrigerant charge Compressor mechanical strain Internal compressor failure First Checks
Check compressor for overheating Verify refrigerant levels Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
72 , High Stage Thermal Cutout
Shutdown The compressor thermal protector has opened during high-stage operation.
Likely Causes
High compressor head pressure Mechanical compressor failure Inadequate compressor cooling First Checks
Check compressor for overheating Verify refrigerant levels Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
73 , Contactor Stuck Closed
Shutdown The control board detects that the compressor contactor remains closed when it should be open.
Likely Causes
Welded contactor points Mechanical binding of contactor Faulty relay on control board First Checks
Inspect contactor for welded contacts Verify contactor coil voltage Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
74 , No Power at Compressor
Shutdown The control board has energized the contactor, but no current is detected moving to the compressor.
Likely Causes
Broken wire to compressor Open internal compressor winding Failed contactor First Checks
Check wiring between contactor and compressor Check compressor internal protector (continuity) Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
81 , Low Stage Thermal Cutout x 3
Lockout, Manual Reset The low stage thermal cutout has occurred three times, triggering a hard lockout.
Likely Causes
Repeated compressor overheating Chronic low refrigerant charge Defective compressor First Checks
Examine compressor history Evaluate system charge and conditions Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
82 , High Stage Thermal Cutout x 3
Lockout, Manual Reset The high stage thermal cutout has occurred three times, triggering a hard lockout.
Likely Causes
Repeated high pressure/heat issues Severe airflow restrictions Compressor failure First Checks
Examine compressor history Check high side system pressures Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
83 , Low Pressure Switch Trip x 3
Lockout, Manual Reset The low pressure switch has tripped three times, triggering a hard lockout.
Likely Causes
Significant refrigerant leak Failed indoor blower motor Severe system restriction First Checks
Perform leak search Check for air flow restrictions Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
84 , High Pressure Switch Trip x 3
Lockout, Manual Reset The high pressure switch has tripped three times, triggering a hard lockout.
Likely Causes
Repeated high pressure events Blocked condenser airflow System overcharge First Checks
Clean outdoor coil Verify outdoor fan motor operation Source: GHAC Knowledgebase, Carrier 25HNB6 Status/Fault Codes
Carrier · Infinity / ComfortLink II / Greenspeed
H7 , Indoor Unit Quantity Mismatch
Shutdown The number of indoor units detected by the system does not match the quantity specified by the S12 and ENC3 rotary switch settings.
Likely Causes
Incorrect manual setting of the IDU quantity switches Communication failure between the outdoor unit and one or more indoor units Indoor unit power supply interruption First Checks
Verify the position of the S12 and ENC3 switches on the outdoor unit Confirm the actual number of indoor units installed in the system Check that all indoor units are powered on and properly addressed Source: Carrier West Training, 38 Series VRF Quick Reference Guide
Carrier · Infinity / ComfortLink II / Greenspeed
P4 , Compressor Protection
Shutdown The system has triggered protection for the compressor or detected a temperature fault.
Likely Causes
Compressor fault Compressor temperature protection First Checks
Check compressor temperature Inspect compressor electrical connections Source: PickHVAC, Mini Split Error Codes (multi-brand)
Carrier · Infinity / ComfortLink II / Greenspeed
P6 , IPM Fault
Shutdown The Intelligent Power Module (IPM) has failed or is malfunctioning.
Likely Causes
Bad Intelligent Power Module (IPM) Overload trip from high amps or thermal event Loss of one leg of 3-phase supply or low incoming voltage Internal winding fault or bearing failure First Checks
Inspect IPM for heat damage Verify electrical connections to the module Source: PickHVAC, Mini Split Error Codes (multi-brand)
Carrier · Infinity / ComfortLink II / Greenspeed
00001 , Low Fuel Level Warning
Warning The fuel tank level is low and requires replenishment to ensure continuous operation.
Likely Causes
Empty fuel tank Fuel leak Faulty fuel sensor First Checks
Check fuel tank level Verify fuel gauge operation Source: Carrier Alarm Codes (Scribd, OEM manual excerpt)
Carrier · Infinity / ComfortLink II / Greenspeed
00002 , Low Engine Oil Level Warning
Warning The engine oil level has dropped below the safety threshold.
Likely Causes
Excessive oil consumption Oil leak Sensor failure First Checks
Check engine oil dipstick Inspect for oil leaks Source: Carrier Alarm Codes (Scribd, OEM manual excerpt)
Carrier · Infinity / ComfortLink II / Greenspeed
00003 , Low Coolant Level
Warning Engine coolant level is insufficient for safe operation.
Likely Causes
Cooling system leak Evaporation over time Failed radiator cap First Checks
Check coolant overflow tank Inspect radiator for leaks Source: Carrier Alarm Codes (Scribd, OEM manual excerpt)
Carrier · Infinity / ComfortLink II / Greenspeed
00004 , Low Refrigerant Level
Warning The system detects a low level of refrigerant in the circuit.
Likely Causes
Refrigerant leak Improper charge during service Sensor malfunction First Checks
Check refrigerant sight glass Inspect for oily residue indicating leaks Source: Carrier Alarm Codes (Scribd, OEM manual excerpt)
Carrier · Infinity / ComfortLink II / Greenspeed
00011 , Check/Low Engine Oil Pressure
Shutdown The engine oil pressure is too low, which can cause internal damage; the unit may attempt to restart.
Likely Causes
Low oil volume Failed oil pump Worn engine bearings First Checks
Check engine oil level Inspect oil filter for blockage Source: Carrier Alarm Codes (Scribd, OEM manual excerpt)
Carrier · Infinity / ComfortLink II / Greenspeed
00012 , High Coolant Temp
Shutdown Engine coolant temperature has exceeded the safety operating limit.
Likely Causes
Blocked radiator Stuck thermostat Water pump failure First Checks
Check radiator for debris Check fan belt tension Source: Carrier Alarm Codes (Scribd, OEM manual excerpt)
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