Electrolux Dryer Error Code F4

The F4 error code on an Electrolux dryer signals a shorted temperature sensor condition. The control board continuously monitors the resistance output of the oven temperature sensor during operation. When a short circuit is detected in that sensor circuit, the resistance drops to an abnormally low level, outside the acceptable range the control expects. The board interprets this as a fault, triggers an audible alarm, and immediately disables all cook or heating modes to prevent uncontrolled temperature conditions.

The temperature sensor, sometimes called a thermistor, works by changing its electrical resistance in proportion to the heat inside the drum or heating chamber. A properly functioning sensor maintains a predictable resistance curve as temperature rises and falls. When the sensor or its wiring develops a short, the control board reads an artificially low resistance value regardless of actual temperature. This makes it impossible for the control to regulate heat accurately, so the safety lockout activates.

The most common causes of an F4 fault include a failed sensor with an internal short, damaged wiring with conductors contacting each other or a grounded surface, or a corroded connector at the sensor or control board end. Pressing the CANCEL key will reset the control to non-cook mode and silence the alarm temporarily. However, if a cook mode is re-engaged and the short still exists in the circuit, the F4 alarm will return immediately. Clearing the code permanently requires identifying and correcting the underlying fault in the sensor or its wiring harness.