NIBE · Heat Pumps
There is a permanent communication fault with the accessory card for DEW (Domestic Hot Water). This issue often points to installation problems, communication circuit faults, or incorrect configuration, blocking DEW functions.
Click steps to track your progress.
Turn off the Heat Pump at the main power supply.
Carefully inspect all communication cables connected to the DEW accessory card for proper installation and secure connections.
Verify that the address on the DEW card's dipswitch is set correctly according to the system's installation manual.
Restore power to the Heat Pump and check if the alarm clears.
If the problem persists, contact a qualified NIBE service technician for diagnosis.