Written by
Maya Chen Editorial TeamPublished October 20, 2026
Error codeFU
ApplianceRefrigerator
Quick answer
FU on an LG refrigerator is a freezer compartment fault with a reset and a set of checks listed by LG.
Model compatibility: LG reuses codes across series and model years, so FU may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
Freezer fault: after 10 minutes the freezer had not dropped below 3.5 degrees Celsius, or it rose above 3.5 degrees Celsius during operation.
FU on an LG refrigerator marks a freezer compartment fault. Ten minutes after the appliance starts, the freezer has not dropped below 3.5 degrees Celsius, or during operation it has climbed above 3.5 degrees Celsius. LG lists it for refrigerators in general.
What LG says to try
Unplug the refrigerator.
Wait 60 seconds, then turn it on again, connected directly to an outlet with no power strips or multiple sockets.
If the error continues, LG’s checks are:
The refrigerator is on, the compressor is running, and cooling and freezing temperatures are in their normal ranges.
The freezer is set to -18 degrees Celsius.
How often and how long the door is opened, since warm air raises humidity and hurts cooling.
Food is not blocking the air vents.
The door closes properly and the gaskets seal. LG describes a paper test: close the door on a piece of paper and try to pull it out.
For malfunction codes, LG says to request service if the problem persists.
Calling about FU? Reach the Los Angeles line at (310) 742-8008 with the model number, the exact code on the display and your earlier steps noted down. Our LG refrigerator repair page has more.
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your LG appliance?
Book a specialist visit for a clear estimate and approval before any repair.
