Display shows dF; unit may run continuously or show inconsistent temperatures; may be related to defrost sensor.

Safety first: Disconnect power before accessing internal panels or control boards. Avoid pulling on wires directly; use connectors.

Step 1 – Locate the defrost thermistor:

• Remove freezer drawers and the rear interior panel to expose the evaporator coil.
• Find the small plastic-encased sensor clipped to the evaporator tubing (this is the defrost thermistor).

Step 2 – Inspect wiring and connections:

• Check the thermistor wires for cuts, pinches, or corrosion.
• Follow the harness to the connector and ensure it is fully seated.
• At the main control board, verify the thermistor connector is secure.

Step 3 – Test the thermistor:

• With the thermistor at a known temperature (e.g., in ice water at 32°F / 0°C), measure resistance with a multimeter.
• Compare the reading to the GE resistance chart (commonly around 16.3 kΩ at 32°F, but verify for your model).
• Replace the defrost thermistor if readings are far from specification or intermittent when the wire is moved.

Step 4 – Control board evaluation:

• If a new thermistor does not clear the dF code, the sensor input on the main control board may be faulty.
• Inspect the board for damage and replace if necessary.

When to call a technician: If you lack the tools or data to test thermistors accurately, or if dF persists after replacement, contact a GE Monogram service provider.