How to Enter Diagnostic Mode on a LG Refrigerator

LG refrigerators report Er-prefix codes on the display panel and store fault history readable through SmartDiagnosis.

Step-by-Step: LG Refrigerator Diagnostics

1
Read the code from the display (Er FF, Er rF, Er dH…). Codes display automatically when faults occur.
2
Use SmartDiagnosis via the ThinQ app — hold the phone near the marked area and follow the prompts to transmit fault history.
3
For fan codes (Er FF / Er rF): open the relevant compartment, listen for the fan, and check for frost buildup on the back panel — icing that jams the fan blade is the leading cause.
4
For defrost codes (Er dH): the defrost heater and thermal fuse on the evaporator can be resistance-tested after removing the freezer back panel.

💡 Good to know: Linear-compressor-era models (2014–2020) with cooling loss but no codes may have a sealed-system issue — that diagnosis needs gauges and a technician, but it is often covered by LG's 10-year compressor warranty.

Found a Code? Look It Up

Once diagnostics shows you a stored code, find its meaning and fix guide in the full LG refrigerator code list. These are the highest-priority codes on this platform:

Er FF

Freezer fan error — fan motor not operating

⚠ High Severity

Er CF

Condenser fan motor error

⚠ High Severity

Er rF

Refrigerator fan error — fresh-food compartment fan not running

⚠ High Severity

Frequently Asked Questions

Why does my LG fridge show Er rF after a power outage? +

The fridge fan may be temporarily iced or the controller flagged a stall during the outage. Power-cycle 60 seconds and watch for 2–4 hours. If Er rF returns, the evaporator fan or its icing problem needs attention.

How to Reset a LG Refrigerator → ← All LG Refrigerator Error Codes