Warning Z1 5213 - Inlet temperature sensor TC0 open circuit

What does 5213 mean?

This warning indicates that the heat carrier return sensor TC0 has an open circuit. This means the sensor is not properly connected, its cable is broken, or the sensor itself is faulty.

• Screw terminal for TC0 on the installer module is not properly tightened.
• Heat carrier return sensor TC0 or its signal cable is broken.
• Defective installer module.

Click steps to track your progress.

1. 1

   Note the warning code 5213.

2. 2

   Contact a qualified Bosch Heat Pump installer or service technician.

3. 3

   The technician will check the sensor's screw terminal, test the sensor cable, and compare the sensor's resistance to specified values.