HVAC FAULT CODES

AMANA ERROR CODES

Data Verified: January 2026

Professional diagnostic codes and troubleshooting steps.

Technical Note: AMANA systems are part of a shared manufacturing platform. These codes are identical for GOODMAN.

Critical Severity
EAF

A2L Mitigation Sensor Communication Fault

Troubleshooting Steps

  • The control board has lost contact with the A2L leak sensor.
  • Check the 4-pin communication cable between the Mitigation Board and the sensor.
  • Ensure the sensor is receiving 5V DC power from the main board.
  • The system will lock out heating/cooling for safety until communication is restored.
Source Reference Goodman R-454B Puron Advance Training
Critical Severity
ELK

Refrigerant Leak Detected (A2L)

Troubleshooting Steps

  • A2L SAFETY: Refrigerant concentration has reached the trip point.
  • The indoor blower is energized to its maximum CFM to dilute the gas.
  • Evacuate and ventilate the mechanical room immediately.
  • Check for leaks at the evaporator coil and flare connections.
Source Reference Goodman R-454B Puron Advance Training
High Severity
b0

Mitigation Board Hardware Fault

Troubleshooting Steps

  • Internal failure on the A2L mitigation logic board.
  • Power cycle the furnace/air handler to reset the logic.
  • If the code returns, the mitigation daughter-card must be replaced.
Source Reference Goodman R-454B Puron Advance Training
High Severity
EE

Compressor EEPROM Error

Troubleshooting Steps

  • The outdoor control board cannot read its internal memory.
  • Turn off the outdoor disconnect for 5 minutes and restart.
  • If the error persists, the outdoor PCB (Printed Circuit Board) is defective.
Source Reference Goodman R-454B Training / Legacy Cross-Ref
Normal Severity
0

Standby Mode / No Call for Operation

Troubleshooting Steps

  • System is working normally but is not receiving a signal from the thermostat.
  • Check thermostat settings (Cool/Heat/Auto) and setpoint.
  • Verify 24V 'R' power is reaching the thermostat.
Source Reference Goodman Legacy Cross-Ref
High Severity
L

Limit Switch Open (Low Airflow)

Troubleshooting Steps

  • The system is overheating. Immediately replace the air filter.
  • Check for blocked return air grilles or closed supply registers.
  • Verify the blower motor is moving sufficient air in heat mode.
Source Reference Goodman Legacy Cross-Ref
Normal Severity
0

Standby Mode / No Call for Operation

Troubleshooting Steps

  • System is working normally but is not receiving a signal from the thermostat.
  • Check thermostat settings (Cool/Heat/Auto) and setpoint.
  • Verify 24V 'R' power is reaching the thermostat.
Source Reference Goodman Legacy Cross-Ref
High Severity
L

Limit Switch Open (Low Airflow)

Troubleshooting Steps

  • The system is overheating. Immediately replace the air filter.
  • Check for blocked return air grilles or closed supply registers.
  • Verify the blower motor is moving sufficient air in heat mode.
Source Reference Goodman Legacy Cross-Ref
Normal Severity
dF

Defrost Cycle Active (Heat Pump)

Troubleshooting Steps

  • System is working normally; the outdoor fan has stopped to melt ice off the coil.
  • If the system stays in defrost for more than 15 minutes, check the defrost thermistor.
  • Verify the auxiliary heat is engaging during defrost to maintain indoor comfort.
Source Reference Goodman Legacy Cross-Ref
High Severity
E0

Low Refrigerant Pressure Lockout

Troubleshooting Steps

  • Check for a refrigerant leak in the evaporator or condenser coils.
  • Verify the indoor blower is running (low airflow can cause low pressure trips).
  • Inspect the liquid line filter drier for a temperature drop, indicating a restriction.
Source Reference Goodman Legacy Cross-Ref
High Severity
3-Flashes

Open Pressure Switch (Inducer On)

Troubleshooting Steps

  • The draft inducer is running, but the pressure switch won't close. Check for a blocked vent.
  • Inspect the small rubber tubing for cracks or water buildup (condensate).
  • Verify the inducer motor is reaching full speed and the wheel is not damaged.
Source Reference Goodman/Amana LED Flash Codes
High Severity
4-Flashes

High Limit Switch Open (Overheat)

Troubleshooting Steps

  • System is overheating. Immediately replace a dirty or restrictive air filter.
  • Check for blocked return air registers or closed supply vents.
  • Verify the blower motor is running and moving air in heat mode.
Source Reference Goodman/Amana LED Flash Codes