Display shows dF periodically and the fan or compressor cycles differently during that time.

Safety first: Unplug before accessing internal components.

• Observe behavior: If dF appears briefly and then clears, this may simply indicate a normal defrost cycle and no repair is needed.
• Check for excessive frost: If dF stays on and the unit warms up, inspect the evaporator for heavy frost (see E4 steps). Excessive frost may indicate a defrost sensor or control issue.
• Sensor replacement: If the unit remains in defrost and never returns to cooling, replace the evaporator/defrost temperature sensor.
• Control board replacement: If a new sensor does not correct the issue, the main control board defrost circuit may be stuck and require replacement.