Alarm 254 - Communication fault to Inverter

What does 254 mean?

The Heat Pump detects a communication fault with the inverter, with Alarm 203 displayed for 20 seconds. This means the main control board is not communicating properly with the inverter unit.

• Poor connection between the main PCB (Printed Circuit Board) and the inverter.
• Inverter is unpowered or has an internal fault.
• Defective inverter unit.

Click steps to track your progress.

1. 1

   Check the main fuses and circuit breakers for the Heat Pump to ensure the inverter is receiving power.

2. 2

   Turn off the Heat Pump at the main power supply for a few minutes, then restore power to attempt a system reset.

3. 3

   If the fault persists, contact a qualified NIBE service technician to check the connections and the inverter unit.