Bosch · Heat Pumps
This alarm indicates a fault with the fluid line sensor TR3 for Heat Pump Z1 while in heating mode. This could be due to a sensor failure or a short circuit in the cable. It triggers after 3 faults in 2 hours, or 15 minutes of continuous failure or short circuit.
Click steps to track your progress.
Locate the I/O board and check the screw terminal connection for sensor TR3 to ensure it is tightened.
If the alarm persists, contact a qualified technician to check the sensor and its cabling.
Contact customer support if the issue continues.