On the covered LG washer platform, FF, u51 means freeze Failure — LG's own wording. LG states this can occur when the temperature inside the washer drops below 1 °C, that water in the drain or inlet hoses may freeze, and that all controls are disabled until the machine rises above 4 °C. First, confirm the weather is actually cold; LG directs a service request if FF appears when it is not.
Differential
Likely causes of “LG washer code FF, u51”, and how to tell them apart
- 1
Ice in the drum and drain hose
What separates it The washer sat in a cold room and shows FF
How to confirm LG says the error occurs when the temperature inside the washer drops below 1 degree C and water in the drain or inlet hoses may freeze
- 2
Frozen inlet hoses or taps
What separates it IE appears after the drum thaws and the drum will not fill
How to confirm Thaw the inlet hoses and taps with warm water
- 3
A washer that is not cold
What separates it FF shows in warm weather, which points to a washer that is not cold
How to confirm LG says to request service if the error occurs when the weather is not cold
Before you touch a setting
Record this first — changing settings destroys the evidence
- The exact characters shown on the display: FF or u51
- The room temperature where the washer sits, since cold can trigger this
- Whether the taps and hoses give water
Try in this order
0 of 6 completedWhat to do first
ReversibleConfirm the weather is actually cold; LG directs a service request if FF appears when it is not.
Correct only the documented fault domain
ReversibleThaw the tub and drain hose with warm water, then test-run the washer once the ice has melted.
Thaw the tub and drain hose
ReversibleLG says the unit will not start, with all controls disabled, until the temperature of the machine rises above 4 degrees C. Open the door, remove the laundry, pour warm water (50 to 60 degrees C) into the drum, close the door and wait 1 to 2 hours for the drain pump to thaw.
Drain the tube
ReversibleOpen the access cover at the lower side, remove the cap from the drain tube, drain any water and securely close the cap; if no water comes out, wait longer.
Test the washer
ReversibleTurn it on and run a Rinse x1 cycle to check it operates without issues.
Thaw the inlet side if IE appears
ReversibleSeparate the inlet hoses from the washer and open the taps; if no water flows, wrap a cloth wet with hot water round the taps for 5 minutes and thaw the hoses in warm water below 50 degrees C, then test with a Rinse and Spin cycle.
Model-specific
What is true of this model and not of its siblings
- Displayed as
- FF or u51.
Stop boundary
When this stops being a self-service repair
- !Do not pour boiling water into the drum, on the hoses or the faucet; LG warns of a burn risk and says to use only warm water
- !Request service if FF appears in warm weather
Evidence ledger
Sources behind this answer
Where the manufacturer's article stops. The 1 and 4 degree thresholds and the 1 to 2 hour thaw are LG's own.
Exact questions
Common questions
What does FF, u51 mean on a LG washer?+
Freeze Failure — LG's own wording. LG states this can occur when the temperature inside the washer drops below 1 °C, that water in the drain or inlet hoses may freeze, and that all controls are disabled until the machine rises above 4 °C.
When will the washer start again?+
When the machine temperature rises above 4 degrees C.
How do I prevent it?+
If you will not use the washer in winter, drain all remaining water from the unit, the drain hose and the inlet hoses.
What if it is not cold?+
Request service.