Washer-dryer will not start a cycle; display shows 1C shortly after pressing Start.

Safety first: Unplug the unit or switch off the dedicated breaker before removing any panels. Turn off both hot and cold water supply valves.

Steps to check and correct:

• Power reset: Disconnect power for 2–3 minutes, then restore power and try a quick wash cycle. Sometimes the control board will clear a transient sensor error.
• Verify water temperature supply: Make sure both hot and cold faucets feeding the GE Profile UltraFast combo are fully open. If only cold is connected, the machine may detect abnormal inlet temperature and trigger 1C.
• Inspect inlet hoses and screens: Shut off water, disconnect hoses at the rear. Check the metal inlet screens on the hot and cold water valves for debris and clean gently with a soft brush. Reconnect hoses firmly.
• Access the inlet valve/thermistor: Remove the top panel (usually a few screws at the back) to access the water inlet valve assembly. Locate the small temperature sensor/thermistor integrated with or near the valve body.
• Check wiring: Inspect the wiring harness from the thermistor to the main control board for loose plugs, corrosion, or damaged insulation. Reseat connectors until they click.
• Test the thermistor (advanced): With power still disconnected, use a multimeter to measure resistance across the thermistor terminals. Compare to GE service specs (typically several kΩ at room temperature). If reading is open, shorted, or far out of range, the sensor is defective.
• Replace faulty parts: If the thermistor or inlet valve assembly is bad, replace the entire water inlet valve assembly with temperature sensor. Transfer wiring one connector at a time to avoid miswiring.

If 1C persists after these checks, the main control board may be misinterpreting the sensor signal and should be evaluated or replaced by a qualified technician.