LG refrigerator codes are short letter pairs: FF, rF, CF and IF are fan faults, dH and dS are defrost faults, FS, rS, rT and IS are temperature sensors, CO and C1 are communication errors, and OFF is demo mode, not a fault. Many fan and defrost codes are caused by frost, so a manual defrost sometimes clears them.
The full code list
| Code | What LG says it means |
|---|---|
| OFF | Demo mode — disables all cooling, meant for retail display |
| Lo / HI | Ambient temperature warning: below −10°C (Lo) or above +50°C (HI) |
| CF | Condenser (cooling) fan error |
| FF | Freezer fan error |
| rF | Refrigerator fan error |
| IF | Ice maker fan error |
| FS | Freezer temperature sensor error |
| rS, r2 | Refrigerator sensor (upper R1 / lower R2) fault |
| dS | Defrost sensor fault |
| rT | Ambient temperature sensor fault |
| IS | Ice maker sensor error |
| It | Ice maker motor error |
| dH | Defrost heater / resistance issue — defrost sensor temperature did not rise as expected (5°C within 80 minutes on LG’s digital list) |
| FU | Freezer cycle error — temperature not dropping or not holding |
| CO | Communication error between main board and display |
| C1 | Communication error between dispenser and display |
| SS | Water tank sensor issue |
| tt | Water tank missing or not inserted correctly |
| gF | Water flow sensor error |
| CH, CL | Refrigerant leak on the high-pressure or low-pressure side |
Fan codes: FF, rF, CF, IF
LG notes that frost buildup around a fan is a common trigger for FF, rF and IF; a blocked condenser fan (CF) makes the compressor work harder. Unplug the fridge, empty the compartments and leave the doors open for several hours to defrost, then restart. Our guide to LG ER FF and ER IF fan faults covers that process, and cleaning condenser coils helps with CF.
Defrost codes: dH, dS
dH means the defrost sensor did not warm as expected during a defrost cycle — a failed heater, bimetal or sensor. dS is a fault in the defrost sensor itself. Both usually need a repair. See LG ER dH explained, and freezer frost buildup if the evaporator is icing over.
Sensor codes
FS, rS, r2, rT, IS and SS point to a temperature sensor outside its expected range. These are not user-serviceable. A refrigerator that is warming at the same time is covered in our refrigerator troubleshooting guide.
Codes that are not faults
OFF is demo mode: the fridge is not cooling because it was set to display mode, so check the manual for how to switch it off (it is a control-panel setting, not a repair). Lo and HI are warnings about the room temperature — a garage fridge in a freezing or very hot space triggers them. tt is only a water tank that is missing or not seated. Also check ice-bin position if the ice maker stops, and see ice dispenser not working.
Cycle and refrigerant codes
FU (the freezer cannot reach or hold temperature), CH and CL (refrigerant leak codes) and communication codes CO and C1 call for a professional. LG states that CO has no home troubleshooting step. Given the cost of a sealed-system repair, look at the repair cost guide and repair or replace guide first.
When to call for service
Unplug the fridge for a few minutes and restart it once; if the same code returns, note it and book service. Meanwhile move perishable food to another fridge or cooler.
