INT COM (green) LED not lit - No communication with inverter

What does INT COM LED off mean?

The green INT COM LED on the base board (AA2) is off, indicating that there is no internal communication between the Heat Pump's base board and the inverter. This is critical for compressor control.

• No communication with the inverter.
• Poor connection between the base board and the inverter.
• Inverter unpowered or defective.

Click steps to track your progress.

1. 1

   Check the main circuit breaker and fuses for the Heat Pump and the inverter to ensure stable power supply.

2. 2

   Turn off the Heat Pump at the main power switch for a few minutes, then turn it back on to attempt a system reset.

3. 3

   If the INT COM LED remains off, contact a qualified NIBE service technician to inspect the connections and the inverter unit.