- Appliances
- Ovens
F20
LG F20 on a double oven range: lower door lock failure
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
On an LG double oven range, F20 means the lower oven door locking system has failed. Press CLEAR/OFF and try the function again; if it returns, turn the circuit breaker off for 30 seconds.
Safety first
Stop and check this first
- Do not force the lower oven door if it stays locked, especially after high temperature use: let it cool and book service.
Safe checks you can perform
- Which oven shows the fault
- Lower door closure
- CLEAR/OFF and 30 second reset
Leave these tasks to a qualified professional
- Do not attempt this professional task: Lock test after the repair
- Do not attempt this professional task: Lock mechanism check
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Lock test after the repair
What they doTo finish, the technician starts a function that locks the lower door and checks it locks, unlocks and shows no F20.
They must show youthe door locking and unlocking with no code.
In writingthe test carried out, the result and the date.
Lock mechanism check
What they doWith the range isolated, the technician inspects the lower door lock mechanism and its position switch, and tests their operation and wiring with a multimeter.
They must show youthe lock and wiring measurements against LG's specification.
In writingthe result and, if the lock is replaced, its part number and the reason.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Which oven shows the fault
- Who:
- you, no tools.
- How:
- photograph the display and confirm it reads F20 and not F10, which LG uses for the upper oven door.
- Result that matters:
- knowing which door the technician must check.
- If it is F20:
- the fault is in the lower oven; go on to the door closure.
- If it is F10:
- that is the upper oven; tell the service centre exactly that.
- Evidence to keep:
- photo of the display.
Evidence: LG Range - Error Codes List
Lower door closure
- Who:
- you, with the oven cold.
- How:
- open the lower oven door, remove any tray or utensil sticking out and close it fully without forcing it.
- Result that matters:
- ruling out anything blocking the closure.
- If something blocked it:
- remove it and repeat the function after CLEAR/OFF.
- If it closes properly or the door is locked and will not open:
- do not force it and go on to CLEAR/OFF.
- Evidence to keep:
- note of how the door was.
Evidence: LG Range - Error Codes List
CLEAR/OFF and 30 second reset
- Who:
- you, at the control panel and the breaker panel.
- How:
- press CLEAR/OFF and repeat the function; if F20 returns, turn the range breaker off for 30 seconds and back on.
- Result that matters:
- whether the lock recovers after LG's reset routine.
- If F20 clears:
- use the oven normally and watch whether it returns.
- If F20 remains:
- LG says the unit needs service; book the repair.
- Evidence to keep:
- time of the tests and the result.
Evidence: LG Range - Error Codes List
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Appliances
- Brand
- LG
- Product type
- Ovens
Known code variants
- 20
- A21
- calentador Cointra F20
- cocina LG error F20
- code erreur F20 chaudière Vaillant
- code erreur F20 lave-linge Siemens
- codice E20 Siemens
- codice F20 Vaillant
- código E20 Siemens
- Cointra F20
- Cointra water heater F20
- CPE T F20
- E00-20
- erreur E20 Siemens
- Error F20 caldera
- error F20 lavadora Siemens
- Error F20 Saunier Duval
- errore F20 caldaia Vaillant
- errore F20 lavatrice Siemens
- F 20
- F20 Siemens
- Fehlercode F20 Vaillant
- Glow worm boiler F20
- Glow worm F20
- Glow-worm F.20
- Glow-worm F20
- Glow-worm F20 overheat
- lavadora Miele anomalía de calentamiento
- LG F20 bloqueo puerta horno inferior
- LG F20 lower oven door lock
- LG horno F20
- LG oven error F20
- LG range F20
- Miele F20 no calienta
- Miele F20 not heating
- Miele lavadora F20
- Miele Thermostop
- Miele washer F20
- Miele washing machine heating fault
- panne F20 Vaillant
- Saunier Duval F20
- Siemens E20
- Siemens F20
- Siemens Fehlercode E20
- Siemens Waschmaschine Fehler F20
- Siemens washer F20
- Siemens washing machine E20
- Supreme E TS F20
- Thema NOx F20
- Vaillant boiler F20
- Vaillant F.20
- Vaillant F20
- Vaillant Fehler F20
What it means
LG US defines F20 as a door locking system failure in the lower oven; the same fault in the upper oven is F10. The routine is to press CLEAR/OFF and try the original function again; if the code reappears, turn the circuit breaker off for 30 seconds and back on. If it continues or you cannot do the steps, LG says service is required. The code means the lock did not behave as the electronics expected: something stopping the door closing fully, the lock mechanism, its connection or the board can all play a part.
Warnings and stop conditions
- Mediumeditorial warning
Do not force the lower oven door if it stays locked, especially after high temperature use: let it cool and book service.
Evidence: LG Range - Error Codes List
Symptoms and causes
Probable causes · in order
- Door not fully closed or obstructedPossible
A tray or utensil stopping the lower door from closing fully. Ruled out by checking the closure before repeating the function.
Evidence: LG Range - Error Codes List
- Lock mechanism or its connectionPossible
If the door closes properly and F20 returns after the reset, the technician must check the lock and its wiring.
Evidence: LG Range - Error Codes List
- Lock control on the boardPossible
With the mechanism and wiring correct, the fault may lie in the board that drives it.
Evidence: LG Range - Error Codes List
Virtual technician
Does F20 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
LG · 2026 · official_doc
Was this entry useful?