Washer stops with E12, often during heating phase, sometimes accompanied by lukewarm water

Safety first: Unplug the washer and allow it to cool before accessing the heater area.

Step-by-step checks:

• Locate NTC sensor: Remove the rear panel. The NTC is usually clipped into the heater bracket at the bottom of the tub.
• Check connection: Ensure the NTC plug is fully seated and free of corrosion. Clean and reseat if necessary.
• Measure resistance: Disconnect the NTC and measure its resistance at room temperature. Compare to Blomberg specifications. If reading is near 0 Ω (short) or infinite (open), replace the NTC.
• Inspect wiring: Follow the NTC wires to the control board, checking for damage or loose connectors.
• Board diagnosis: If a known-good NTC and wiring are present but E12 remains, the control board's sensor input may be defective and require replacement.