Error Code: EC 5A – Failure of Enthalpy Inlet Temperature Sensor

Error Code: EC 5A – Failure of Enthalpy Inlet Temperature Sensor

What this means:
The enthalpy inlet temperature sensor is returning an abnormal voltage — either below 0.06V or above 4.94V. This indicates an open or short circuit, or a failed sensor. The system shuts down to protect itself from operating with inaccurate airflow or humidity temperature data.

Try this first (quick reset):

1. Turn off power to the unit completely.

2. Wait 2 full minutes.

3. Turn the unit back on and check the display.

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

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

Next steps (for technicians):

1. Check the sensor wiring to the PCB:

   • Ensure the enthalpy inlet temperature sensor is properly connected.

   • If loose or damaged → repair or replace the connection wires.

2. Measure the resistance of the sensor:

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

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

What you might need:

• Enthalpy inlet temperature sensor

• Connection wires

• Indoor PCB

Helpful tip:
This sensor helps control system efficiency in variable humidity and airflow conditions. It is especially critical in energy-saving or high-precision systems.

Click here to view the detailed guide.TS18