LG Refrigerator Error Code 21

Error code 21 on an LG refrigerator indicates a fan motor system abnormality in the CF (freezer compartment) section. The control board has detected a problem with the fan motor feedback signal line, a missing or broken motor wire, or a defect in the fan motor itself. This error means the refrigerator cannot confirm the fan is operating correctly, which can impact freezer and fresh food compartment temperatures.

A malfunctioning CF compartment fan can reduce or eliminate proper air circulation in the freezer, which will eventually affect food preservation in both the freezer and fresh food sections. It is not recommended to rely on the refrigerator for storing perishable or frozen food for an extended period while this error is active. Address the fault as soon as possible to prevent food spoilage.

A power reset by unplugging the refrigerator for a few minutes may temporarily clear the error code from the display, but the code will return if the underlying fault is still present. Error 21 is triggered by an active hardware condition, such as a missing feedback signal or a non-functioning motor, so clearing it without repairing the cause is only a temporary measure. A proper repair of the wiring or motor is required for the code to stay cleared.

Some causes of error 21 are DIY-friendly, such as reseating a loose wire connector or inspecting the fan wiring harness for visible damage. If the issue is a failed fan motor, the motor assembly can often be replaced by a confident DIYer with basic tools. However, if the control board is suspected, professional diagnosis is recommended before replacing expensive parts.

If the fix is simply reseating a loose connector, there is no parts cost. A replacement CF compartment fan motor typically costs in the range of $30 to $100 for the part, depending on the specific model. If a technician is needed for diagnosis and installation, total repair costs including labor generally fall in the $100 to $250 range, though control board replacement would add significantly to that estimate.