HVAC Toolkit
R

Rheem Error Codes

Inverter Mini-Splits & Air Conditioners ยท USA

Prefixes: E=System/Sensor, F=Sensor/Protection, P=Protection, H=Status

E-Series (System/Sensor Errors)

Code Description Possible Cause Action
E1 Indoor/outdoor communication error Communication wire fault or PCB failure between units Check communication wiring, connectors, and control boards on both units
E2 Room temperature sensor failure Indoor room thermistor open or short circuit Check sensor wiring and resistance, replace thermistor if faulty
E3 Evaporator coil sensor failure Indoor coil thermistor open or short circuit Inspect sensor connection on evaporator, replace if out of spec
E4 Outdoor coil sensor abnormality Outdoor unit condenser coil thermistor failure Check outdoor coil sensor wiring, measure resistance, replace sensor
E5 Over-voltage or under-voltage protection Input power supply voltage out of acceptable range Check incoming voltage with multimeter, verify power supply stability
E6 Evaporator temperature sensor open circuit Indoor evaporator thermistor disconnected or broken Inspect sensor wiring, check connector, replace thermistor
E7 Indoor/outdoor unit miscommunication Serial communication failure between units Check communication cable, verify polarity, inspect PCB connectors
E8 Overheating protection Compressor or system temperature exceeds safe limit Check refrigerant charge, condenser airflow, compressor condition
EC Refrigerant leak detection Refrigerant leak sensor triggered or low charge detected Perform leak test, repair leak, recharge system to nameplate spec
E0 EEPROM parameter error Indoor or outdoor unit EEPROM data corrupted Power cycle the unit, replace main PCB if error persists

F-Series (Sensor/Protection Codes)

Code Description Possible Cause Action
F1 Outdoor ambient temperature sensor fault Outdoor ambient thermistor open or short circuit Check sensor wiring on outdoor unit, replace thermistor
F2 Condenser coil temperature sensor fault Condenser coil thermistor (T3) open or short circuit Inspect sensor on condenser coil, replace if resistance out of spec
F3 Discharge temperature sensor fault Compressor discharge thermistor (T5) open or short circuit Check sensor on compressor discharge line, replace if needed
F4 Outdoor unit EEPROM error Outdoor PCB EEPROM data corrupted or missing Power cycle outdoor unit, replace outdoor PCB if error persists
F5 Outdoor fan speed out of control Outdoor fan motor not running at expected speed Check fan motor, wiring, and fan blade for obstruction

P-Series (Protection Codes)

Code Description Possible Cause Action
P0 Inverter module (IPM) protection IPM overcurrent or overheat protection triggered Check compressor windings, inverter board, and heat sink cooling
P1 Over-voltage / under-voltage protection DC bus voltage out of normal operating range Check input voltage, rectifier circuit, DC bus capacitors
P2 Compressor top high temperature protection Compressor shell temperature exceeds safe limit Check refrigerant charge, suction superheat, and compressor valves
P3 Outdoor high/low pressure protection Refrigerant pressure exceeds high or low pressure limit Check refrigerant charge, condenser/evaporator, and expansion valve
P4 Compressor drive error Inverter compressor drive circuit malfunction Check inverter board, compressor winding insulation, and wiring
P5 Condenser coil high temperature protection Condenser coil temperature too high in cooling mode Clean condenser coil, check outdoor fan, verify refrigerant charge

Other Codes

Code Description Possible Cause Action
DF Defrost mode active Normal defrost cycle running in heating mode No action needed, wait for defrost cycle to complete
02 High pressure fault High pressure switch tripped or pressure too high Check condenser, outdoor fan, refrigerant overcharge, non-condensables
21 Low pressure control open Low pressure switch tripped or loss of charge Check for leaks, verify refrigerant charge, inspect expansion device
83 Condenser coil temperature fault Condenser sensor reading abnormal Check sensor placement, measure resistance, replace if out of range
84 Outdoor ambient temperature fault Outdoor temp sensor reading out of range Check sensor placement, ensure not near heat source, replace if faulty

H-Series (Status/Protection)

Code Description Possible Cause Action
H1 Defrost protection Outdoor coil frosted, triggering defrost Normal in heating mode; if frequent, check outdoor coil sensor and refrigerant

L-Series (Inverter Codes)

Code Description Possible Cause Action
L4 Locked rotor condition Compressor rotor mechanically locked Check compressor, starting components, and refrigerant pressures

Rheem Troubleshooting Tips

Before Calling for Service

  • Turn off unit, wait 5 minutes, then restart - some errors auto-reset
  • Check and clean air filters - many errors caused by restricted airflow
  • Verify power supply voltage is within specification
  • Check circuit breaker and disconnect switch
  • Note the exact error code and when it occurs for technician

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