LG Refrigerator Error Code R-DEFROST HEATER ERROR

This error means the refrigerator compartment defrost heater ran for 80 minutes continuously without completing a defrost cycle. The control board logged the fault because the evaporator temperature never reached the expected cutoff point. Possible causes include a failed thermal fuse, a defective heater element, a shorted or broken wire, or a displaced defrost sensor. The refrigerator compartment cooling will typically degrade as frost accumulates on the evaporator coils.

A failed defrost heater will cause frost to build up on the evaporator coils over time, which progressively reduces cooling performance. The refrigerator and freezer compartments may not hold proper temperatures, putting stored food at risk. It is best to address the error promptly rather than continue operating the unit, especially if you notice reduced cooling or unusual frost buildup.

A power reset may temporarily clear the error code from the display, but it will not fix the underlying hardware failure. The fault will return the next time the refrigerator attempts a defrost cycle and the heater again fails to complete within 80 minutes. The actual cause, whether a blown thermal fuse, failed heater, or damaged wiring, must be diagnosed and repaired to permanently resolve the error.

A knowledgeable DIYer can perform the initial resistance check at Main PCB connector CN70 by measuring between the White and Orange wires. A 0-ohm reading points to a heater or wiring short, while an infinite reading indicates an open circuit from a blown thermal fuse or broken wire. Replacing a thermal fuse or inspecting wiring for damage is within DIY range, but replacing the heater element or PCB may require more comfort with appliance disassembly and electrical testing.

Repair costs depend on the failed component. A replacement thermal fuse is typically inexpensive, ranging from roughly $5 to $25 for the part alone. A defrost heater element can cost between $20 and $80 in parts. If professional labor is needed, expect an additional $80 to $200 depending on your location and the technician's rates. Wiring repairs may fall on the lower end of total cost if no major parts need replacement.