HVAC Toolkit

Samsung Error Codes

Complete fault code reference for Samsung mini-splits and air conditioners

Quick Reference: E1xx = Indoor | E2xx = Outdoor | E3xx = Compressor | E4xx = Fan | E5xx = Protection | E6xx = Valves

E1xx - Indoor Unit Errors

Code Description Possible Cause Solution
E101 Communication error (indoor-outdoor) No communication between indoor and outdoor units Check communication wiring, verify connections at both units
E102 Communication error (wired remote) Wired controller communication fault Check remote wiring, verify polarity
E103 Signal from wired remote interrupted Intermittent communication Check wire connections, replace damaged wiring
E104 Indoor address error Duplicate or incorrect address setting Reset indoor unit address, check DIP switches
E121 Indoor room temperature sensor fault Thermistor open, short, or out of range Check thermistor resistance, replace if faulty
E122 Indoor coil (evaporator) sensor fault Evaporator thermistor malfunction Check and replace coil thermistor
E123 Indoor outlet air sensor fault Discharge air thermistor failure Check and replace outlet sensor
E128 Indoor coil inlet sensor fault Inlet thermistor malfunction Check and replace sensor
E130 Indoor EEPROM error Memory chip failure Replace indoor PCB
E134 Indoor unit model mismatch Incorrect system configuration Verify correct model pairing
E151 Indoor fan motor current overload Fan motor drawing too much current Check fan motor, replace if faulty
E152 Indoor fan motor IPM fault Fan inverter module failure Check motor, replace indoor PCB
E153 Indoor fan motor speed abnormal Fan not reaching target speed Check for obstruction, test motor
E154 Indoor fan motor position fault Hall sensor or position feedback error Check motor connections, replace motor
E162 Louver motor error Swing/vane motor stuck Check motor operation, reset louver
E163 Drain pump error Drain pump failure or float switch Check pump, clear drain line
E170 Indoor unit over-current PCB or component failure Check all components, replace PCB

E2xx - Outdoor Unit Errors

Code Description Possible Cause Solution
E201 Outdoor unit communication error Communication with indoor unit lost Check wiring, verify connections
E202 Outdoor PCB communication fault Internal PCB communication failure Check PCB connections, replace if needed
E221 Outdoor ambient sensor fault Outdoor temperature thermistor failure Check and replace ambient sensor
E226 Condenser middle sensor fault Mid-coil thermistor failure Check and replace sensor
E231 Discharge temperature sensor fault Compressor discharge thermistor failure Check and replace discharge sensor
E235 Top of compressor sensor fault Compressor shell thermistor failure Check and replace sensor
E237 Suction pipe sensor fault Suction line thermistor failure Check and replace suction sensor
E240 High pressure sensor fault HP transducer failure Check and replace HP sensor
E241 Low pressure sensor fault LP transducer failure Check and replace LP sensor
E250 Outdoor EEPROM error Memory chip failure Replace outdoor PCB
E251 Outdoor unit capacity mismatch System configuration error Verify outdoor capacity matches indoor total
E254 Outdoor inverter PCB mismatch PCB compatibility issue Verify correct replacement PCB

E3xx - Compressor Errors

Code Description Possible Cause Solution
E301 Compressor overcurrent trip Compressor drawing excessive current Check refrigerant charge, compressor condition
E302 Compressor overcurrent (CT) Current transformer detected overload Check compressor windings, voltage
E303 Compressor inverter DC link high High bus voltage Check input voltage, capacitors
E304 Compressor inverter DC link low Low bus voltage Check power supply, capacitors
E305 Compressor IPM fault Inverter power module failure Check compressor, replace outdoor PCB
E306 Compressor inverter over-voltage Input voltage too high Check and correct supply voltage
E307 Compressor inverter under-voltage Input voltage too low Check and correct supply voltage
E308 Compressor startup failure Compressor failed to start Check wiring, capacitors, compressor
E320 Compressor rotor position error Inverter cannot detect rotor Check compressor windings
E323 Compressor current sensing fault CT sensor malfunction Check CT, replace PCB if needed

E4xx - Fan Motor Errors

Code Description Possible Cause Solution
E401 Outdoor fan overcurrent Fan motor drawing too much current Check for obstruction, test motor
E402 Outdoor fan IPM fault Fan motor inverter module failure Check motor, replace outdoor PCB
E403 Outdoor fan startup failure Fan motor failed to start Check motor windings, connections
E404 Outdoor fan speed abnormal Fan not reaching target RPM Check for obstruction, test motor
E405 Outdoor fan position fault Hall sensor or feedback error Check motor connections
E416 Sub-fan motor fault Secondary fan motor error Check sub-fan motor and wiring

E5xx - System Protection

Code Description Possible Cause Solution
E501 High pressure protection Head pressure too high Clean condenser, check charge, verify fan
E502 High pressure switch open HP switch tripped Identify cause, reset after fixing
E503 Low pressure protection Suction pressure too low Check for leaks, verify charge
E504 Discharge temperature protection Compressor overheating Check superheat, refrigerant charge
E505 Compressor top temperature high Compressor shell overheating Check charge, ambient conditions
E506 Outdoor unit over-temperature PCB or heat sink too hot Check ventilation, clean unit
E508 Freeze protection activated Evaporator coil freezing Check airflow, filter, charge
E509 Inverter overheat protection Inverter module too hot Check ventilation, reduce load
E554 Power phase missing Three-phase power issue Check all phases at power supply
E556 Power phase reverse Phase sequence incorrect Swap any two phases

E6xx - Valve Errors

Code Description Possible Cause Solution
E601 EEV (electronic expansion valve) fault EEV not responding Check EEV coil and wiring
E602 4-way valve fault Reversing valve not switching Check solenoid coil voltage
E604 LEV fault Linear expansion valve error Check LEV motor and wiring
E605 Oil return valve fault Oil return solenoid error Check valve and coil

Samsung Error Code Troubleshooting Tips

Reading Error Codes

  • • Error codes display on the wired remote or indoor LED
  • • Press the test/diagnosis button to enter service mode
  • • Samsung SmartThings app can also display fault codes
  • • Check outdoor unit display for additional codes

Common Solutions

  • • E101: Communication wire issue - check connections
  • • E121/E122: Sensor faults - check thermistor resistance
  • • E301-E320: Compressor issues - check power and windings
  • • E501-E509: Protection faults - address root cause first

Error Code History

Samsung units store recent error codes in memory. To view error history, enter service mode by pressing specific button combinations on the wired remote. This helps diagnose intermittent faults that may have self-cleared.