Thermador induction range or cooktop displays Er27 and zones may not operate.

Safety first: Disconnect power at the breaker before accessing internal boards.

• Power reset: Turn off power for 10 minutes, then restore and test.
• Review recent service: If a board was recently replaced, verify that the correct Thermador part number was installed for your exact model and that any required configuration or coding steps were performed.
• Check connectors: Reseat communication harnesses between the UI and power modules.

Persistent Er27 typically requires reprogramming or replacement of the control board with the correct, model-specific part. This is usually performed by an authorized Thermador technician with access to service tools.