On the covered LG refrigerator, FU means a freezer compartment fault — LG's own wording: after 10 minutes of starting, the freezer temperature has not dropped below 3.5 °C, or during operation it has risen above 3.5 °C. First, unplug the refrigerator, wait 60 seconds and reconnect it to a direct outlet — LG is specific that it must not be on a power strip or multiple socket.
Differential
Likely causes of “LG refrigerator code FU”, and how to tell them apart
- 1
A freezer that does not cool below 3.5 degrees C
What separates it FU shows and the freezer stays warm ten minutes after start
How to confirm LG says after 10 minutes of starting, the freezer has not dropped below 3.5 degrees Celsius, or it rose above 3.5 during operation
- 2
Blocked vents or a leaky door
What separates it Food sits in front of the vents or the gasket does not seal
How to confirm Check food is not blocking air vents and that the door closes with sealed gaskets
- 3
A door opened too often
What separates it The door is opened often or left ajar, which points to a door opened too often
How to confirm Opening the door lets warm humid air in; the longer it stays open the more cooling suffers
Before you touch a setting
Record this first — changing settings destroys the evidence
- The exact characters shown on the display: FU
- The freezer set temperature at the time of the fault, with the date
- Note whether the compressor is running before you start troubleshooting
- Whether the gaskets pass the paper test
Try in this order
0 of 6 completedWhat to do first
ReversibleUnplug the refrigerator, wait 60 seconds and reconnect it to a direct outlet — LG is specific that it must not be on a power strip or multiple socket.
Correct only the documented fault domain
ReversibleIf the error continues, LG directs you to check the freezer is set to −18 °C, how often and how long the door is opened, whether food is blocking the air vents, and whether the door gaskets seal — testing a gasket by closing a sheet of paper in the door and feeling it resist.
Reset with a direct outlet
ReversibleUnplug the refrigerator, wait 60 seconds and turn it on again, connecting it to a direct outlet without power strips or multiple sockets.
Check the running state
ReversibleMake sure the refrigerator is on, the compressor is running, and the freezer is set to -18 degrees Celsius.
Check airflow and door use
ReversibleCheck food is not blocking the air vents, and consider how often and how long the door is opened.
Test the gaskets
ReversibleClose a piece of paper in the door and try to pull it out; it should resist if the seal is good.
Model-specific
What is true of this model and not of its siblings
- Displayed as
- FU.
- Parts named
- Compressor; door gaskets.
Stop boundary
When this stops being a self-service repair
- !Move food to another freezer if it is thawing
Evidence ledger
Sources behind this answer
Where the manufacturer's article stops. The 3.5 degree, 10 minute and paper-test details are LG's own.
Exact questions
Common questions
What does FU mean on a LG refrigerator?+
a freezer compartment fault — LG's own wording: after 10 minutes of starting, the freezer temperature has not dropped below 3.5 °C, or during operation it has risen above 3.5 °C.
What is the paper test?+
Close paper in the door and pull; it should resist.