NIBE · S-Series Heat Pumps
The Heat Pump's internal monitoring system has detected an open-circuit or short-circuit on the input for sensor BT84. This indicates a problem with the sensor itself or its wiring.
Click steps to track your progress.
Visually inspect the wiring connected to sensor BT84 for any signs of damage or loose connections.
Turn off the Heat Pump at the main power switch for a few minutes, then turn it back on to reset the system.
If the alarm persists, contact a NIBE service technician to check or replace the BT84 sensor.