LG Refrigerator Error Code R-16

The R-16 error code on an LG refrigerator indicates a fault in the refrigerator compartment defrost heater circuit, also referred to as the R-DEF heater circuit. This heater is responsible for melting frost accumulation off the evaporator coils in the fresh food section during scheduled defrost cycles. When the control system detects an open circuit, abnormal resistance, or a defrost cycle that fails to complete within 80 minutes of continuous heating, it triggers the R-16 code and logs the fault.

The primary diagnostic entry point involves the main PCB connectors CN70 and CN71. With both connectors separated from the PCB, a technician checks continuity between the CN70 White wire and the CN71 Orange wire. The measured resistance should fall within 110 ohms plus or minus 7 percent, which places the acceptable range between approximately 102.3 ohms and 117.7 ohms. A reading outside this range indicates a problem somewhere in the heater circuit, including the heater element itself, the thermal fuse, or the wiring between those connectors.

Common failure points include loose or disconnected wire harness connectors at the PCB, damaged or cut wiring in the harness, and a blown thermal fuse, which is a one-time protective device that opens permanently when subjected to excess heat. A defective heater element that has gone open circuit will also produce this code. In some cases the heater and wiring test within spec but the defrost cycle still times out, which can point toward a control board fault or an unusually heavy frost load that prevents the evaporator from reaching the termination temperature within the 80-minute window.