LG Refrigerator Error Code E 25

The E 25 error code on LG RSG5B-series refrigerators indicates a fridge compartment defrost failure caused specifically by overheating during the defrost cycle. Under normal operation, the defrost heater activates periodically to melt frost buildup on the evaporator coils, and a defrost limiter or thermistor monitors temperature to prevent the heater from exceeding safe operating limits. When the control board detects that temperatures have climbed beyond the acceptable threshold during this cycle, it logs E 25 and terminates the cycle to protect the refrigerator's internal components.

The primary diagnostic entry point is the MAIN PCB connector CN70. Disconnecting this connector and measuring resistance between the Orange and White wire terminals reveals the condition of the defrost heater circuit. A reading of 0 ohms indicates a direct short in the heater element itself. An infinite resistance reading points to either a broken wire in the harness or a blown thermal limiter or thermistor that has opened the circuit. These two failure modes require different repair approaches, so this resistance check is critical before replacing any parts.

Overheating during defrost can also result from a malfunctioning defrost thermostat that fails to cut power to the heater at the correct temperature, or from a defrost control relay on the main PCB that stays energized too long. In some cases, a restriction in airflow around the evaporator caused by excessive ice buildup from a prior failed defrost cycle will cause the heater to work harder and longer, pushing temperatures into the fault range. Identifying whether the fault is a heater short, an open circuit, or a control-side timing issue determines the correct repair path.