Display shows dF frequently and freezer temperature rises during these periods.

Safety First: Unplug the freezer before testing defrost components.

On some Frigidaire models, dF simply indicates the unit is in defrost. If the code remains for an abnormally long time and the freezer warms excessively, there may be a fault.

• Step 1 – Observe duration: Normal defrost lasts 20–40 minutes. If dF remains for hours and the compressor does not restart, proceed.
• Step 2 – Check evaporator temperature: Remove the interior rear panel. If the evaporator is warm and free of frost but the unit stays in dF, the control may be stuck in defrost.
• Step 3 – Test defrost thermostat: With the coil cold, verify the thermostat closes (0Ω). A thermostat stuck open can prevent proper defrost termination.
• Step 4 – Inspect heater: Check the defrost heater for signs of overheating or damage. Measure resistance to confirm it is within spec.
• Step 5 – Control board: If heater and thermostat are good, replace the electronic control board, which may not be exiting defrost correctly.