Perm. com. error PCD4 — Permanent communication fault with 4-pipes passive cooling accessory card

What does 94 mean?

There is a permanent communication fault with the accessory card for 4-pipes passive cooling (PCD4). This issue often points to incorrect installation, communication circuit faults, or incorrect configuration, blocking the cooling function.

• Communication cables to the card are incorrect or incorrectly installed.
• Fault in the communication circuits in the accessory-, input- or display card.
• Incorrect address set on the dipswitch of the accessory card.
• The 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 4-pipes passive cooling accessory card (PCD4) for proper installation and secure connections.

3. 3

   Verify that the address on the accessory 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.