Forum Index > Range, Oven & Cooktop Repair

F9 error code

<< < (2/3) > >>

So went to customers home and tested the oven according to the service manual and it seems to lead me to the relay board. However all the service manual says is to try the relay board and if that doesn't work replace the main PCB, does anyone know if there is a way to narrow it down as this is a non-warranty job? Also after I tested things and power was reapplied I tried the oven and it started to preheat on bake and I went to see if it was heating and the door was locked, I'm not sure if that clarifies anything because both the main pcb and the relay board control the door lock. Any thoughts?

If you can get access to the back of the relay board, check for voltage to coil of the relay. If there's voltage and the relay is not closing, you know the relay is bad.  I'm thinking the door locking was just a power failure self check, assuming it eventually unlocked on it's own.

You have to check for your low voltage to your relay pcb. This can be tricky due to the High Voltage side ;D. These relays are often put under massive stress and they seem to be failure prone! :D I also assume you checked your safety thermostats? If the customer recently put this into SELF CLEAN the safety may very well have tripped. This will cause a no heat condition but NOT shut down the rest of the stove. (IN WALL models only unless i'm mistaken)

I am heading out on this exact problem Tue.  Customer said she had relay board and thermostat replaced  6 months ago and has the F-9 again.  She's not happy. :tickedoff:
Does anyone have the manual for this one?  Have they upgraded the relay board to handle the stress you think?
Have never worked on one of these so any help would be appreciated! :thanks:

LG Oven Model# LWS3081ST.  I had the problem that so many others seem to have with this oven: F9 code. I read many blogs and tried several different parts and fixed the problem myself.  It appears that the issue occurs when the oven gets too hot, most often after a self cleaning cycle.  There are two parts which look identical 1. Thermal fuse, which costs about $3, and connects two wires under a panel on the top of the oven. 2. THERMOSTAT, which costs about $12 and also connects two wires under a panel on the back side of the oven. 

In my case it was the THERMOSTAT was the problem.  After taking apart my oven the THERMOSTAT was slightly deformed after being exposed to extreme heat and it broke.  I purchased a new one from, Part Number AP5672246. (After reading several forums I tested the PCB, Oven Sensor, Thermal fuse, and door lock mechanism and they were all fine.)

If you are handy and you want to fix yourself: turn off the circuit breaker power to oven, pull oven completely out of cabinet cavity, completely remove sheet metal panel on top and back of oven (held on by several small screws), locate THERMOSTAT which is attached to back of oven by 1 tiny screw, pull to remove the two wires attached and reattach the wires to new thermostat, re-assemble oven. 


[0] Message Index

[#] Next page

[*] Previous page

Go to full version