LG Dryer FO Error
LG's UK list names the code FO — “Filter Out”. Its US list renders the same display as F0 and pairs it with the flashing Insert Filter message. Same code, three renderings.
What to check first
- Remove the lint filter and reinsert it fully into the housing — LG's whole published fix.
- FO, F0 and flashing INSERT FILTER are one code in three renderings.
- Never run the dryer with the filter out — the stop is a protection.
- FO with the filter seated → service.
FO is the dryer reporting its lint filter: LG's UK list says an FO error — or a flashing INSERT FILTER — indicates the lint filter should be checked to ensure it is inserted properly, and that when it is not, the sensor inside the dryer will display FO and the dryer will stop working. The whole published fix is mechanical: remove the lint filter and reinsert it into the filter housing. If the code or the flashing message continues after that, LG's line is repair service.
Safety first
- The dryer stopping on FO is a protection, not a nuisance: a dryer run without its filter passes lint straight into the duct — the buildup behind the <a href="/lg-dryer-error-codes/d80/">d80</a> family of warnings. Never run the dryer with the filter removed to “test” it.
- Stop condition: stop using the machine and unplug it — and do not run it again until it has been checked — if you smell burning, see smoke, find damaged electrics (a scorched plug, a melted or cut cable), or water is leaking in quantity.
Common causes
The filter was removed and not refitted
The everyday case: the filter comes out for cleaning after every load, and one day it does not go back in. The dryer detects the empty housing at the next start and posts FO instead of running.
The filter is in, but not fully seated
LG's wording is “not inserted properly” — a filter sitting slightly proud of its housing reads the same as a missing one to the sensor. Reseating, firmly, is the whole check.
Step-by-step checks
- Remove the lint filterTake the filter out of its housing completely — do not just push on it. (And since it is out: clean it. LG's method is warm water and a soft brush, dried fully.)
- Reinsert it into the filter housingPush the filter fully home into the housing — LG's stated fix for FO on both lists.
- If FO or the flashing message continues, book serviceLG's endpoint: with the filter correctly inserted and the display still posting FO, the unit may require a repair service — the sensing side is then the suspect, and it is not a user part.
When to call a technician
Service is LG's stated endpoint when FO persists with the filter properly inserted. Quote the display exactly as your machine renders it — FO, F0 or INSERT FILTER — they are the one code, and saying which form you see tells the technician your model's rendering.
Model differences
| What you have | What changes |
|---|---|
| Display reads F0 (zero) | The same code: LG's US list renders it F0 where its UK list writes FO. Letter O, number 0 — one fault, the filter. |
| Flashing INSERT FILTER instead of a code | LG files the flashing message as the same display as FO — same check, same fix. |
| A Check Filter light as well | Different display: Check Filter is the clean-the-filter reminder. FO means the filter is out or unseated, and the dryer will not run. |
One-page checklist — FO
- Display form noted (FO / F0 / flashing INSERT FILTER)
- Filter removed, cleaned, and reinserted fully into the housing
- Dryer not run with the filter out — not even to test
- Code persists with filter seated → service booked
Official LG references
Frequently asked questions
Is it FO or F0 on my display?
Both — by region of LG's documentation. Its UK list writes FO and expands it as Filter Out; its US list writes F0 for the same display and the same fault. The check does not change: the lint filter is out or not inserted properly.
The filter is in. Why FO?
LG's wording covers it: “not inserted properly” triggers the same display as missing. Take the filter fully out and reinsert it into the housing; if FO continues with the filter correctly seated, LG's line is repair service.
Can I run the dryer without the filter until I replace it?
The dryer will not let you — LG states it stops working when the filter is not inserted properly, and that stop is deliberate: unfiltered lint goes straight into the exhaust duct. Refit or replace the filter; do not defeat the sensor.