LG Refrigerator Error Code F1+F3

The F1+F3 error code on an LG refrigerator indicates a failure of the single motor damper system. Specifically, the control board drives the damper motor for up to 2 minutes and expects to detect a reed switch signal confirming the damper has moved between its open and closed positions. If the reed switch ON/OFF transition is never detected within that 2-minute window, the board registers this fault. The damper controls airflow between the freezer and fresh food compartments, so a failure here directly impacts temperature regulation throughout the refrigerator.

The most likely mechanical causes include a damper motor that has seized due to ice buildup around the assembly, physical damage to the motor or its mounting, or a burned or open coil inside the motor itself. When the motor cannot turn, the reed switch mounted on the damper never changes state, and the board cannot confirm movement. Ice accumulation is particularly common in humid environments or when a door seal has been compromised, allowing moisture to reach the damper housing.

On the electrical side, the fault can originate from a failed photo coupler (driving IC) on the control board that is responsible for sending the drive signal to the damper motor. If the photo coupler fails, the motor never receives the command to move regardless of its physical condition. Diagnostic steps should address both the mechanical and electrical possibilities: inspect the damper assembly for ice, physical damage, and coil continuity, then evaluate the driving IC on the control board if the motor itself checks out.