F9 appears soon after starting bake
The code shows up early and the oven never really gets warm.
Start here: First check for a full loss of bake heat: a dead bake element on an electric oven or a non-lighting bake igniter on a gas oven.
Oven error code troubleshooting
LG Oven F9 Error Code
Direct answer: An LG oven F9 error code usually means the oven did not heat up fast enough during preheat. The most common causes are a weak or failed oven heating element, a bad oven igniter on gas models, or an oven temperature sensor that is reading wrong.
Most likely: Start by confirming whether your oven is electric or gas, then watch what happens during preheat. If it never gets hot, heats very slowly, or the heat looks uneven, that points you toward the failed heating part instead of the control.
This code is really a timing complaint. The oven expected to see temperature rise and it did not happen the way it should. Reality check: if the oven still sort of heats, that does not rule out a bad part. Common wrong move: clearing the code over and over without watching the actual burner or element during preheat.
Don’t start with: Do not start by ordering an oven control board. F9 is much more often caused by a heating problem the control is reporting, not the control itself.
Most common fix pathCheck whether the oven bake heat source is working fully during preheat.
Before buying partsReset power once, then test a normal bake cycle and watch the heating pattern.
Last reviewed: 2026-04-17
What the F9 code looks like in real use
F9 appears after a long preheat
The oven warms some, but it is slow and never seems to catch up.
Start here: Look for a weak heating source or a temperature sensor reading that is off enough to stop the cycle.
Broil works but bake does not
The top heat works, but baking fails or throws F9.
Start here: Focus on the oven bake element for electric models or the oven bake igniter for gas models.
Code started after a brief outage or breaker trip
The oven worked before, then began showing F9 after power was interrupted.
Start here: Do a full power reset first, then retest. If the code returns, move to heating and sensor checks.
Most likely causes
1. Failed oven bake element on an electric oven
F9 often shows when the oven cannot build heat during preheat. A bake element can fail completely or split and still look only lightly damaged.
Quick check: Start bake and look for normal bottom heat. If the oven stays cool or the element shows damage, this is a strong lead.
2. Weak or failed oven bake igniter on a gas oven
A gas oven can show F9 when the igniter glows weakly or takes too long to open the gas valve, so preheat drags out and times out.
Quick check: Start bake and watch through the bottom panel area if visible. A glow with no flame, delayed flame, or repeated clicking without proper ignition points here.
3. Out-of-range oven temperature sensor
If the sensor reports the wrong temperature, the control may think the oven is heating incorrectly and stop with F9 even when some heat is present.
Quick check: If the oven heats but the displayed temperature and actual cooking performance are clearly off, the sensor moves up the list.
4. Loose connection or failed oven control relay
This is less common, but a bad connection or relay can keep power from reaching the heating circuit even though the display still works.
Quick check: Suspect this only after the heating parts and sensor do not explain the problem, or if heating cuts in and out unpredictably.
Step-by-step fix
Step 1: Reset the oven once and confirm the exact failure pattern
A brief power glitch can leave a false code behind, but if F9 comes back you need to know whether the oven is not heating at all, heating weakly, or reading temperature wrong.
- Turn the oven off at the control.
- Shut power off to the oven at the breaker for about 5 minutes.
- Restore power and set a normal bake cycle at a moderate temperature.
- Stay nearby for the first several minutes and note whether the oven begins heating, heats slowly, or throws F9 again right away.
Next move: If the oven preheats normally and the code stays gone, the issue may have been a one-time control glitch or power interruption. If F9 returns, move on and watch the actual heat source behavior during preheat.
What to conclude: A reset can clear a nuisance fault, but a repeat code usually means the oven still is not seeing the temperature rise it expects.
Stop if:
- The breaker trips again.
- You smell burning insulation or see smoke.
- The display goes dead or starts acting erratically beyond the F9 code.
Step 2: Separate electric from gas and watch the bake heat source
This is the fastest way to avoid guessing. F9 is usually tied to the bake side not doing its job during preheat.
- If you have an electric oven, start bake and look for bottom heat after a few minutes. On exposed-element designs, look for even heating across the element. On hidden-element designs, feel carefully for rising heat in the cavity without touching interior parts.
- If you have a gas oven, start bake and listen and watch for ignition. A healthy bake igniter should lead to flame fairly quickly, not just sit glowing weakly.
- If broil still works, note that. Strong broil with weak or no bake usually narrows the problem to the bake circuit, not the whole oven.
Next move: If the bake heat source comes on strongly and the oven heats at a normal pace, the sensor becomes more likely than the main heating part. If there is no bottom heat, delayed ignition, weak heating, or obvious uneven heating, you have a likely component failure in the bake circuit.
What to conclude: No heat or weak bake heat points first to the oven bake element on electric models or the oven bake igniter on gas models.
Step 3: Inspect the bake component for visible damage or obvious failure
A quick visual check often confirms the problem without meter testing. Heating parts usually leave physical clues when they fail.
- Turn power off at the breaker before opening anything.
- For an electric oven, inspect the oven bake element for blisters, cracks, splits, burn spots, or a section that has broken open.
- For a gas oven, inspect the oven bake igniter area for heavy wear, cracking, or signs it has been overheating, if accessible after removing the oven bottom panel with power off.
- Check the wiring you can safely see for loose terminals, heat damage, or a burnt connector near the bake circuit.
Next move: If you find a damaged bake element or a clearly failed igniter, that is enough to support replacing that part. If the heating part looks normal and wiring looks intact, keep going. Sensors can fail without visible damage.
Step 4: Check whether the oven temperature reading makes sense
If the oven does heat but F9 still appears, the control may be getting a bad temperature signal from the oven sensor.
- Run a bake cycle and pay attention to whether the oven cavity gets obviously hotter than the display behavior suggests, or stays much cooler than expected.
- If you already own a basic multimeter and can safely access the sensor with power off, disconnect the oven temperature sensor and check resistance at room temperature. A reading far from the expected room-temperature range points to a bad sensor.
- If you do not have a meter, use cooking results and preheat behavior as your clue: slow but steady heat with odd temperature reporting often points to the sensor rather than the bake heater itself.
Next move: If the sensor reading is clearly out of range or the oven temperature behavior is obviously inaccurate, replacing the oven temperature sensor is the supported next move. If the sensor checks out and the bake component also seems good, the problem shifts toward wiring or the oven control.
Step 5: Replace the failed bake-side part, or stop before chasing the control
By this point you should have a supported direction. The common fixes are the bake element, bake igniter, or temperature sensor. Control problems are real, but they are not the first bet on F9.
- Replace the oven bake element if your electric oven has no proper bottom heat and the element is visibly damaged or tests open.
- Replace the oven bake igniter if your gas oven shows weak glow, delayed ignition, or no reliable bake flame during preheat.
- Replace the oven temperature sensor if the oven heats but temperature behavior is clearly wrong and the sensor tests out of range.
- After replacement, restore power, run a normal bake cycle, and confirm the oven reaches temperature without returning to F9.
- If the bake component and sensor both check out but the oven still will not send power to the heating circuit, stop and schedule appliance service for wiring or control diagnosis.
A good result: If the oven preheats normally and the code stays gone, the repair is complete.
If not: If F9 returns after a confirmed good heating part and sensor, the remaining likely causes are a wiring fault or oven control issue that needs deeper diagnosis.
What to conclude: You want to finish with the part the symptoms actually support, not jump straight to the most expensive electronic part.
Replacement Parts
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FAQ
What does F9 mean on an LG oven?
It usually means the oven did not reach the expected temperature in the allowed time during preheat. In plain terms, the control asked for heat and did not see the temperature rise it expected.
Can I keep using the oven with an F9 code?
Not a good idea. If the oven is heating poorly, cooking will be unreliable, and if the problem involves ignition delay, wiring damage, or overheating parts, continued use can make it worse.
Is F9 usually a bad control board?
No. On this kind of complaint, the control is often just reporting that preheat failed. The bake element, bake igniter, or oven temperature sensor are more common causes than the control itself.
How do I know if my oven has a bad bake element or a bad sensor?
If an electric oven has little or no bottom heat, suspect the oven bake element first. If the oven does heat but temperatures are clearly wrong or inconsistent, the oven temperature sensor moves higher on the list.
What if broil works but bake gives F9?
That usually points to the bake side specifically, not the whole oven. On an electric oven, check the oven bake element. On a gas oven, check the oven bake igniter for weak or delayed ignition.
Will unplugging or resetting the oven fix F9?
It can clear a one-time glitch after a power interruption, but if the code comes back during the next bake cycle, there is usually a real heating or sensing problem behind it.