Washer-dryer combo stops and displays F23; may not fill or may stop heating water.

Safety first: Disconnect power and allow any hot water to cool before working near the heater.

• Locate NTC sensor: Remove rear panel. The NTC is usually mounted in the heater housing or directly in the tub wall near the heater.
• Inspect wiring: Check the connector at the sensor for corrosion or looseness. Reseat firmly.
• Test sensor: Remove the sensor and measure resistance with a multimeter. Compare to the service manual chart (typically around 20kΩ at room temperature, decreasing as temperature rises). If open, shorted, or far out of range, replace the sensor.
• Check for scale buildup: Heavy mineral deposits on the sensor or heater can cause inaccurate readings. Descale the tub with a washer cleaner if needed.