Induction cooktop zone displays E4 and does not heat, sometimes intermittently.

Safety first: Disconnect power at the breaker and allow the cooktop to cool completely before opening the unit.

• Power cycle: Turn off power for 5 minutes, then restore and test. Transient faults can occasionally clear.
• Check for overheating causes: Confirm that cooling vents are not blocked and that the fan runs when zones are active.
• Internal inspection (advanced): Remove the cooktop from the counter per the service instructions. Remove the bottom cover to access the induction modules.
• Inspect sensor connection: Locate the small NTC temperature sensor on the affected module (usually clipped to the heat sink). Ensure its connector is fully seated on the board and the sensor is firmly attached to the metal surface.
• Look for damage: Check for burnt spots, cracked components, or melted connectors on the module.

If the sensor and wiring appear intact but E4 persists on the same zone, replace the affected induction power module or its temperature sensor assembly, depending on Thermador's parts breakdown for your model.