Error Code: EC 52 – Outdoor Coil Temperature Sensor (T3) Error

Error Code: EC 52 – Outdoor Coil Temperature Sensor (T3) Error

What this means:
The system has detected an issue with the T3 sensor — which monitors the outdoor coil temperature. This error is triggered when the sensor's signal voltage is either below 0.06V or above 4.94V, indicating an open or short circuitTS23.

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 the display.

• If the error clears — it may have been a temporary fault.

• If the error remains — follow the steps below.

Next steps (for technicians):

1. Check the sensor wiring:

   • Ensure the T3 sensor is properly connected to the outdoor PCB.

   • If wires are loose or corroded → repair or replace the connection wires.

2. Measure the sensor resistance:

   • If resistance is out of specification → replace the T3 sensor.

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

What you might need:

• T3 (coil) temperature sensor

• Outdoor PCB

• Connection wires

Helpful tip:
This sensor is often part of a shared harness with T4 and TP. Always verify your model’s sensor configuration before replacing parts.

Click here to view the detailed guide.TS23