Perm. com. error FLM — Permanent communication fault with FLM accessory card

What does 79 mean?

There is a permanent communication fault with the accessory card for FLM (Flow/Level Module). This issue often points to installation problems, communication circuit faults, or incorrect configuration.

• Communication cables to the FLM card are incorrect or incorrectly installed.
• Fault in the communication circuits within the accessory, input, or display card.
• Incorrect address set on the dipswitch of the FLM card.
• The FLM accessory card itself may be faulty.

Click steps to track your progress.

1. 1

   Turn off the Heat Pump at the main power supply.

2. 2

   Carefully inspect all communication cables connected to the FLM accessory card for proper installation and secure connections.

3. 3

   Verify that the address on the FLM card's dipswitch is set correctly according to the system's installation manual.

4. 4

   Restore power to the Heat Pump and check if the alarm clears.

5. 5

   If the problem persists, contact a qualified NIBE service technician for diagnosis.