LG Refrigerator Error Code R1 R2 R3 R4 (blinking pattern 3)

This blinking pattern indicates a defrost system fault. The refrigerator's control board detected that the defrost cycle ran for more than 2 hours without the evaporator temperature reaching 13°C. This points to a failure in one or more components of the defrost circuit, including the defrost heater, thermal fuse, defrost sensor, or heater relay RY5 on the main control board.

Resetting the refrigerator by unplugging it may temporarily clear the displayed fault, but the error will return as soon as the next defrost cycle fails to meet the 13°C threshold within 2 hours. The underlying cause in the defrost circuit must be repaired before the error will stay cleared. Resetting without repair is not a solution.

Repair costs vary depending on which component has failed. Replacing a thermal fuse or defrost sensor is generally inexpensive, with parts typically ranging from $10 to $40 and labor adding $80 to $150 depending on your area. A defrost heater replacement may run $30 to $80 in parts. If the main control board needs replacement due to a failed RY5 relay, costs can range from $150 to $350 or more for parts and labor combined.

Some steps, such as manually defrosting the unit by unplugging it and allowing ice to melt, can be done without specialized tools. However, fully diagnosing the fault requires testing the defrost heater for continuity, checking the thermal fuse, verifying the defrost sensor, and inspecting relay RY5 on the main PWB. These steps involve working with electrical components inside the freezer compartment and are best handled by someone with appliance repair experience and a multimeter.

Continuing to run the refrigerator with an active defrost fault is not recommended. Frost will continue to accumulate on the evaporator coil, progressively restricting airflow and reducing cooling performance in both compartments. Over time, food safety can be compromised as temperatures rise. The unit should be diagnosed and repaired promptly.