LED: INT COM (green) Not lit — No communication with inverter

What does Not lit INT COM (green) mean?

The green INT COM LED on the base board (AA2) is not lit, indicating a lack of communication with the inverter.

• Poor connection between the PCB and the inverter.
• Inverter is unpowered or defective.
• Communication fault on the base board or inverter.

Click steps to track your progress.

1. 1

   Check the indoor module/control module display for communication fault alarms (e.g., Alarm 254).

2. 2

   Verify all supply cables to the Heat Pump are connected, ensuring the inverter has power.

3. 3

   Try resetting the Heat Pump by briefly disconnecting and reconnecting its main power supply (via circuit breaker).

4. 4

   If the LED remains off, contact a qualified technician to inspect the inverter and its connections.