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

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

What this means:
The outdoor coil sensor (T3) is giving a reading that’s either too high or too low for normal operation — likely due to a short circuit, open circuit, or sensor failure. When this occurs, the system shuts down to protect itself.

Try this first (quick reset):

1. Turn off the power completely.

2. Wait 2 full minutes.

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

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

• If the error remains — continue with the troubleshooting steps.

Next steps (for technicians):

1. Check the wiring:

   • Ensure the connection between the T3 sensor and the outdoor PCB is secure and correct.

   • If connections are damaged or corroded → repair or replace.

2. Measure sensor resistance:

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

   • If resistance is normal → proceed.

3. If sensor and wiring are fine but error remains:

   • Replace the outdoor main PCB.

What you might need:

• T3 temperature sensor

• Outdoor main PCB

• Connection wires

Helpful tip:
In some models, T3, T4, and TP are part of a single combination sensor. Always verify whether your unit uses a shared sensor before replacing individual components. The error is triggered when the sensor's voltage falls below 0.06V or exceeds 4.94V.

Click here to view the detailed guide.TS05-ODU