Bosch · Alarm List A/W Split (8754) 2018 01 10
There is a fault with the Z1 condenser inlet (heating) sensor TR7, indicated by an open circuit or short circuit.
Click steps to track your progress.
Check the resistance of the TR7 sensor against the documentation table.
Repair the sensor cable or replace the sensor if faulty.
If the sensor is functional, check the installer board for defects.