sensor fault BT2 — Heating medium return sensor not connected or defective

What does 2 mean?

The BT2 sensor, typically monitoring the heating medium return temperature, is not connected or is faulty. This fault will block additional heating, and the system will use other available sensors for calculations if possible (e.g., BT3, BT63 for VVM 500).

• sensor not physically connected to the Heat Pump.
• Damaged or faulty BT2 sensor unit.
• Loose wiring connection to the sensor.

Click steps to track your progress.

1. 1

   Turn off the Heat Pump at the main breaker for at least 30 seconds.

2. 2

   Inspect the BT2 sensor and its wiring for secure connections and any damage.

3. 3

   Ensure the sensor is correctly installed in its designated position.

4. 4

   Restore power to the Heat Pump and observe if the alarm clears.

5. 5

   If the problem continues, contact a service technician to diagnose or replace the sensor.