Error Code: EC 57 – Refrigerant Pipe Temperature Sensor Error

Error Code: EC 57 – Refrigerant Pipe Temperature Sensor Error

What this means:
The sensor that monitors the refrigerant pipe temperature is either shorted, disconnected, or sending abnormal voltage readings. If the sensor voltage falls below 0.06V or rises above 4.94V, the system will display EC 57 and shut down to prevent incorrect operation.

Try this first (quick reset):

1. Turn off the power to the unit completely.

2. Wait 2 full minutes.

3. Turn the unit back on and check if the error clears.

• If the error clears — the issue was likely temporary.

• If the error remains — follow the steps below.

Next steps (for technicians):

1. Inspect the sensor wiring:

   • Make sure the refrigerant pipe temperature sensor is securely connected to the PCB.

   • If the wiring is loose or damaged → repair or replace it.

2. Measure the sensor’s resistance:

   • If the resistance is outside of normal range → replace the sensor.

   • If the resistance is within range but the error persists → replace the PCB.

What you might need:

• Refrigerant pipe temperature sensor

• Indoor or outdoor PCB (depending on sensor location)

• Connection wires

Helpful tip:
Sensor-related codes like EC 57 often come down to loose connections or damaged wires. Always test resistance before deciding to replace the control board.

Click here to view the detailed guide.TS18