On the covered LG range or oven, F9 means the Upper Oven Not Heating Properly — LG's own wording. First, note whether the oven heats slowly or not at all. Then: LG's two steps for F9 are to press CLEAR/OFF and try the oven again, then, if F9 comes back, to turn the range's breaker off for 30 seconds and on again — LG's own sequence.
Differential
Likely causes of “LG range or oven code F9”, and how to tell them apart
- 1
The upper oven is not heating properly
What separates it F9 shows and the oven heats slowly or never reaches the set temperature
How to confirm LG words F9 as the upper oven not heating properly
- 2
A heating element or an igniter that has weakened
What separates it The oven takes far longer to preheat than before
How to confirm Watch whether the element glows red or the burner lights
- 3
A power supply that is short of voltage
What separates it The surface burners or the lower oven also heat poorly
How to confirm Check that the breaker is fully on; a range needs a full supply
- 4
A heating control or relay fault
What separates it The element never comes on
How to confirm Service diagnosis with a meter
- 5
A one-off glitch
What separates it F9 appears once and clears
How to confirm Reset as LG says and retry
Before you touch a setting
Record this first — changing settings destroys the evidence
- That the code reads F9 and not F6 or F19
- Whether the oven heats at all, or heats slowly
- Whether the lower oven and the surface burners heat normally
- How long the oven took to preheat compared with before
Try in this order
0 of 7 completedWhat to do first
ReversibleNote whether the oven heats slowly or not at all.
Correct only the documented fault domain
ReversibleLG's two steps for F9 are to press CLEAR/OFF and try the oven again, then, if F9 comes back, to turn the range's breaker off for 30 seconds and on again — LG's own sequence.
Press CLEAR/OFF
ReversibleThen try the original function again.
Reset at the breaker
ReversibleOff for 30 seconds, then on.
Preheat once
ReversibleNote the time to reach the set temperature.
Compare the other burners
ReversibleAnd the lower oven.
Use an oven thermometer
ReversibleTo see the real temperature.
Model-specific
What is true of this model and not of its siblings
- What the code says
- LG's list calls F9 the upper oven not heating properly, which is a performance fault rather than a total failure: the oven tries and does not reach temperature. That matters, because a range that has lost one leg of its supply, or a single element that has weakened, can still produce some heat.
- How to read the symptom
- Run a normal bake at 350 degrees Fahrenheit and put an oven thermometer on the middle rack. Note how long it takes to reach 350 and how far below the setting it settles. A slow climb and a low plateau point to a weak heat source; a thermometer that agrees with the display but takes a long time points to the same.
- Power matters
- An electric range needs a full 240 volt supply. If a breaker has half tripped or a connection has loosened, the range may work in part. If the cooktop elements also heat poorly, tell the technician, because that points away from the oven.
- A gas model
- On a gas range the burner must light and stay lit. Look for a flame that is weak, yellow or uneven, and note any smell; if you smell gas, leave and call your gas utility.
- Records for service
- Write the model number, the code and the preheat times. LG's repair booking asks for the model number and the code, and the technician can then bring the right part.
- What not to do
- Do not run self-clean to try to clear the code, since it asks for far more from the heating system than a normal bake.
Evidence ledger
Sources behind this answer
Exact questions
Common questions
What does F9 mean on a LG range or oven?+
the Upper Oven Not Heating Properly — LG's own wording.
Can I keep using the oven?+
A slow oven gives uneven results; use a thermometer and avoid relying on it.
Does F9 appear when the power is low?+
A weak supply can make heating slow, so check the breaker.