FF on an LG refrigerator means the freezer fan is not reporting the speed it should. It is one of the codes LG's Smart Diagnosis gives up when you hold the test button, and it almost always arrives with a fridge that has stopped getting properly cold.
FF appears on 8 jobs in our refrigerator records, across 188 LG refrigerator jobs.
How customers describe it:
"I have an LG Fridge model LFCS22520S that is giving me a smart diagnosis error code of FF. it feels like the fridge is not getting as cold especially on top. freezer seems fine."
"Fridge has error code FF. This has happened in the past — it is always due to icing up of the freezer fan."
The fan is usually not broken
That second quote is a customer who had been through it before, and they are right. It is the most useful sentence in this whole set of jobs.
On our FF calls the fan motor is rarely dead. It is jammed in ice.
Here is why. Behind the back wall of your freezer sits the evaporator coil and, beside it, the fan that blows air across it. That cold air is then ducted up into the fresh-food compartment. The whole assembly goes through a defrost cycle several times a day to melt the frost that builds on the coil.
When the defrost system falters — a failed heater, a failed thermostat or sensor, a blocked drain that refreezes — frost keeps building until it reaches the fan blade. The blade touches ice, the motor stalls or slows, the control board reads the wrong speed back from it, and you get FF.
The fan is the victim, not the culprit. This matters because replacing a fan on a fridge with a defrost fault buys you a few months at most.
The giveaway numbers
One of our jobs recorded the temperatures, and they tell the story better than any description:
"FF code indicates fan failed. Freezer measures 30°F, fridge measures 52°F, indicates not cooling."
The freezer is only a little warm. The fridge is dangerously warm — 52°F is above the safe zone for food. That lopsidedness is the signature of a stalled freezer fan: the freezer still has the coil right there beside it and stays cool by proximity, while the fresh-food compartment, which depends entirely on air being blown to it, climbs.
If your freezer seems nearly fine and your fridge is the problem, suspect the fan before you suspect the compressor. A dead compressor warms both.
The same job also noted "loud noise". That noise is the blade clipping ice on every rotation.
What we replaced
- The freezer fan motor, on one job.
- Two fans on one machine — the evaporator fan and the ice-maker fan both, on an LMXS30776D. If the frost got bad enough to stop one, it is worth checking the other while the back panel is off.
Where a fan was replaced, the defrost side needs checking in the same visit, or the new fan ices up on the same schedule as the old one.
Why you may also see "E" at the same time
Two of our jobs showed both codes: "error codes E and FF", and "code E for the refrigerator and code FF for the freezer".
That pairing is not two faults. It is one fan failing to serve two compartments — the freezer reports its fan, the fresh-food side reports that it is not getting cold. On both of those jobs the customer also had no water and no ice from the dispenser, which is what happens when the whole evaporator area is packed with frost.
If a power reset makes it go away
Two of our FF calls arrived like this: "Went into E FF error twice yesterday but not in error right now after power reset", and another where the code was gone by the time we got there.
A reset does not fix an iced fan — it just lets the ice melt a little. Unplugging the fridge warms the freezer enough that the blade frees itself, the code clears, and you get a few good days until the frost reaches it again.
One of those customers is worth quoting in full, because it cuts against the story above and they deserve the benefit of the doubt: they noted "there isnt that much ice build up either in the freezer", and the job was cancelled because "error codes went away, he will contact us back if anything changes." A fan can also fail electrically, or report badly, with no dramatic frost at all. If you look and the freezer is genuinely clear, say so to whoever you call — it changes where they start.
So if yours clears on a reset, you have confirmed the diagnosis rather than solved it. The question to answer is why the defrost cycle is not keeping up.
What you can safely check
- Put a thermometer in each compartment and leave it four hours. Write the numbers down — a warm fridge with a cold-ish freezer is the pattern above.
- Listen at the back of the freezer with the door open and the light switch held in (on most LG models the fan runs with the door open if you defeat the switch). Silence, or a buzzing without airflow, is a stalled fan.
- Feel for airflow at the vents inside the fresh-food compartment. Nothing coming out is the clearest sign.
- Look for frost where it should not be — a solid white sheet across the back wall of the freezer rather than light powder.
- Try a manual defrost. Empty both compartments, unplug the fridge, and leave the doors open for 24 hours with towels down. If it runs normally afterwards and FF returns within a few weeks, the defrost system is the real fault.
- Check the vents are not blocked by packaging pressed against the back wall. It happens, and it is free to fix.
Call a tech when FF returns after a defrost, when you can hear the blade hitting something, or when your fridge compartment is above 40°F — at that point it is a food-safety problem, not an inconvenience.
The models we've seen it on
LFCS22520S, LMXC23796S, LFXS26973S, LFXS28596S and LMXS30776D — LG's French-door and side-by-side families.
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Related pages
- Refrigerator Not Cooling But Freezer Works — the exact symptom FF produces
- Refrigerator Ice Buildup in Freezer — the frost that jams the fan
- Ice Maker Not Working — often the same frozen evaporator
- Refrigerator Repair in the SF Bay Area & Peninsula — our full refrigerator service
- LG Appliance Repair — every LG appliance we service
Frequently asked questions
What does FF mean on an LG refrigerator? FF is a freezer fan fault, reported through LG's Smart Diagnosis. The control board expects a speed signal back from the evaporator fan and does not get the right one, so it logs FF.
Does FF mean I need a new fan? Not necessarily, and on our jobs usually not. The fan is more often jammed by ice than electrically dead. One of our customers, who had been through it twice, put it exactly right: it is always due to icing up of the freezer fan. The underlying fault is then in the defrost system.
Why is my fridge warm but the freezer still cold with an FF error? Because the freezer sits next to the evaporator coil and stays cool by proximity, while the fresh-food compartment depends entirely on the fan blowing cold air up to it. On one of our jobs the freezer measured 30°F and the fridge 52°F — that lopsided pattern is the signature of a stalled freezer fan.
My LG shows FF and E together — is that two problems? No, one. The freezer reports its fan fault and the fresh-food side reports that it is not getting cold, because a single fan serves both. On both of our jobs with that pairing the water and ice dispenser had also stopped, which happens when the evaporator area is packed with frost.
FF cleared after I unplugged the fridge — is it fixed? No. Unplugging warms the freezer enough for the iced-up fan blade to free itself, so the code clears and you get a few good days. The frost will reach the blade again. It confirms the diagnosis rather than fixing it.
Is a warm fridge with an FF error a food-safety problem? Above 40°F, yes. One of our jobs measured the fresh-food compartment at 52°F. If yours is in that range, move perishable food elsewhere and get it looked at rather than waiting.