Error Code: EH C3 – Refrigerant Sensor Out of Range

Error Code: EH C3 – Refrigerant Sensor Out of Range
Applies to LETO and AURA Series

What this means:
The indoor unit is not receiving valid feedback from the refrigerant sensor. This could mean the sensor is disconnected, malfunctioning, or reporting values outside its expected range.

Try this first (easy fix):

1. Turn off 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 goes away — the system is good to go.

• If it remains — continue with the steps below.

Next steps (for technicians):

• Check the wiring between the refrigerant sensor and the indoor PCB.

• Confirm that all connections are secure and properly seated.

• If the wiring is fine:

  • Replace the refrigerant sensor.

  • If the error still appears, replace the indoor main PCB.

What you might need:

• Refrigerant sensor

• Indoor PCB

• Communication wires

Helpful tip:
This error typically occurs when feedback from the sensor is missing for over 150 seconds, or when a fault signal is received continuously for 10 seconds. Always check wiring first before replacing any parts.

Click here to view the detailed guide.TS05-N10