Error Code: EH 3A – External Fan DC Bus Voltage is Too Low Protection

Error Code: EH 3A – External Fan DC Bus Voltage is Too Low Protection

What this means:
This error occurs when the indoor unit receives a DC bus voltage signal from the external fan module that is abnormally low, or if the unit receives no feedback for over 150 seconds. It indicates a communication or power supply issue between the indoor PCB and the external fan moduleTS35.

Try this first (quick reset):

1. Shut off the power supply to the unit.

2. Wait 2 minutes.

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

• If the error clears — the system may have stabilized.

• If the error remains — proceed with the troubleshooting steps below.

Next steps (for technicians):

1. Check the ENC1 setting:

   • If incorrect → reset ENC1 to factory specification.

2. If ENC1 is correct but error remains:

   • Replace the indoor main PCB.

What you might need:

• Indoor main PCB

Helpful tip:
EH 3A is closely related to EH bA and EH 3b. All three relate to voltage or communication faults with the external fan module. Always confirm ENC1 settings before proceeding to PCB replacement.

Click here to view the detailed guide.TS35