I have an LG wall oven showing an F9 code (oven not heating) any ideas as to what is wrong? I need parts manual and wiring schematic but I suppose that is hard to get. Internet search yielded one answer that on there oven it was the thermostat. They replaced it and it worked a while and the thermostat went out again. The parts diagram on this website show two thermostats. Also should I replace the thermistor? I am mechanically inclined and should be able to do the repairs myself, I think.

Have an LWD3081st Double Wall Oven. We received an error code of F9 on the top oven. The error happened after a self cleaning. I believe it was an issue with too high heat. We replaced the thermistor from the inside. That did not solve the problem. I just pulled the oven and replaced the thermostat (tiny $12 part). That did solve the problem. However, could have been a combination of both parts. It is a very simple fix once you pull out the oven and take off the back plate. I recommend buying both parts and replacing cine the cost is so low. BTW, it would have cost $200+ if we called an outside service. Well worth the trouble. NOTE: I also used double stick velcro to re-attach the trim below. This way it will be easy to take off if the repair is needed again. I recommend NEVER using self clean on the LG LWD3081st.