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2025-07-18: PSA: If your LG LSG4513BD (or related model) stove keeps throwing an F9 Error when trying to start the oven... read on... I may have a solution for you (or your oven may have a completely different issue). This should probably be a recall problem, but since it fails correctly and 'safely' and a properly functioning GFI would have clearly indicated the problem, I'm not quite sure how this should be handled... Our stove has been throwing these errors occasionally for quite some time and it has been impossible to track down up until this point. The stove always seemed to work on the second start and there was no obvious gas smell indicating a ignition failure. We could also see the ignitor was clearly working every time. Two things helped this time. First, I found a Service Manual for our stove! (Google MFL37118341) Second, our stove wouldn't stop throwing the F9 error and my supper was delayed. (That is a good motivator for guys if food motivates you!) This particular error is an 'Oven - no heating error' and is triggered when the oven does not rise in temperature more than 10°F over 5 minutes. So its a gas problem, right? Well not exactly - you see all the top burners work fine and the broiler works fine. It is just the convection oven.
Lets throw up an image of the tag on this particular oven. Then I'll show the problem and explain how the failure worked [or didn't].
Here is the entire stove side problem. This ignitor wire has worn through and is grounding out. But the ignitor works perfectly fine! Since the fiberglass insulation is always fuzzy, this was incredibly hard to spot without knowing what to look for.
Here is how the wire was laying when it was found. This image also shows you exactly how the wire got worn through and what it was grounding out on! The solution is to either replace the whole ignitor assembly or re-sheath the wire. Since I have access to the proper sheathing and I didn't feel like paying/waiting for a new ignitor (or disassembling the stove to replace it) I re-sheathed the wire with some fiberglass tubing. I then made sure the wire does not run over the sharp point by routing it up and over the broil burner gas tube (see image below - red line)
So lets look at the wiring diagram to see what was happening because this is an interesting failure mode:
This stove is fed by 120VAC Single Phase. Nothing special there; it draws maybe 3-4 amps. I've traced the wires in question here to make it a little easier to follow. Hot (red wire) comes in from the plug, winds its way around and ends up at Relay 11 - Convection Heater. When turned on, power exits via the orange wire to the Ignitor. Power is then fed through the safety valve via the yellow wire from the Ignitor. Keep this in your head: Ignitor and valve are wired in series. If ignitor stops working or opens, the valve will not work at all. (But in our case the ignitor works fine!) Lets back up and trace the neutral wire (Blue wire). This runs directly down to Relay 100 - Oven Enable. It then goes out to the bottom side of both valves (Cyan Wire). Did you spot what was happening yet?
It makes perfect sense once explained. In our case, we need to back up a little further... In fact the whole way to the electrical panel in our house. In that panel, ground wires (green) are typically bonded to neutral wires (white). This stove has a properly wired ground wire which grounds the whole stove. (However it does not seem to have a properly functioning GFI). The wire that shorted out on the metal frame of the stove is the yellow wire. So when it shorts, we have power [hot] coming in on orange, powering the ignitor and exiting via the yellow wire to the stove frame which ends up on the ground circuit. The circuit is complete and no power ever reaches the gas valve.... Until you slam the oven door and the wire shifts ever so slightly breaking the ground path. It was that simple... and that hard to find!
P.S. And yes, I did replace the GFI too. This particular failure will not happen again if I can help it!