• Please note, some of the links on our site are affiliate links (Learn More)

LG Oven LWC3063ST stops heating during use

tchp

Premium Member
Joined
Nov 8, 2021
Messages
6
Location
Oregon, USA
Model Number
LWC3063ST
Brand
LG
Age
1-5 years
Our LG wall oven LWC3063ST is not quite two years old. It worked fine until last May, when it would suddenly play an error chime during baking (although a couple of times it happened during the pre-heating), and the oven would go into cooling mode. You could turn the oven back on, but often it would just repeat the same error moments or minutes later. Turning the oven off at the 50amp breaker for extended periods (sometimes over 24 hrs) did not seem to help anything. Ultimately, by October it could end up shutting down 10 times during a 20 minute period of baking, and after multiple instances of this we stopped using the oven as it was not really worth dealing with. The error for the oven that was reported via the LG Diagnostic App was "F18: An error in the steam generator temperature sensor has been detected". I have not been able to find any online references to this specific error online, in which the temperature sensor being cited is for the "steam generator". I did however purchase a regular OEM temperature sensor for the oven to see if that might solve the issue, but like other people having this same issue have reported, simply putting in a new oven temperature sensor did not help.

I then scheduled a service call with an LG authorized service center. The technician reviewed the error codes stored in the oven and also noted that he was not seeing reference in LG's product literature to the F18 error being one that involved the "steam generator", and that it was normally just the code for the oven's typical temperature sensor. He did order a new control board (the one that is installed behind the area at the top of the oven behind the touch display screen.) After he installed it, I tested the oven that evening baking potatoes at 425 degrees for one hour, and it did not have any errors or issues. A couple days later we baked a pizza for about 20 minutes at 425, also with no errors. But then the problem came back last night, and we had two of the exact same F18 errors as before during a 20 minute baking session.

I rescheduled the technician to come back, but it does not look like there is any chance the oven will be fixed this month. In any case, the other instances of this issue I have seen online at forums seem to involve people having multiple control boards replaced, sometimes multiple times, and one person who had an oven still under warranty actually was finally given a new one. So, at this point I kind of have a pessimistic outlook for this issue being solved conclusively anytime in the near future, and was hoping that someone might have experienced this same issue and found the root cause of it. My technician had said when he replaced the control board that he was pretty sure it would solve the issue, and that if it did not they would probably have to go back to LG and ask them if they could offer any guidance.

Thanks,
Thomas

Note: Our wall oven does have some kind of steam cooking feature, which we have never used, in which you fill a water cartridge that you insert into an area behind the oven door.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
125,433
Location
McMullen Valley, Arizona
I couldn't locate the schematic for this model, but usually the culprit is the board with the relay's on it.

What is the part number of the board he replaced?

Here's the main PCB board for your model:

Here's the PCB board with all the relay's on it for your model:

I couldn't locate anything on the F18 error either.

Jake
 

tchp

Premium Member
Joined
Nov 8, 2021
Messages
6
Location
Oregon, USA
Thank you. The board that was replaced was the main PCB that you first mentioned, EBR85707901, as I saved the packaging for it.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
125,433
Location
McMullen Valley, Arizona
Ok, then its most likely that PCB board with all the relay's on it.

Jake
 

tchp

Premium Member
Joined
Nov 8, 2021
Messages
6
Location
Oregon, USA
I bought a new PCB board EBR85708001, and installed it yesterday. I baked some potatoes for 1 hour and had no issues. Today my wife used the oven to bake something, and the oven issued the F18 error once, putting the oven in Cooling Mode, so she had to restart the oven and continue baking.

So, at this point both of the main PCB boards have been replaced, and the error "F18: An error in the steam generator temperature sensor has been detected" is still being issued. However, things do seem improved from when the oven had reached it worse point, where you could restart it but the oven would almost immediately issue the error again repeatedly.

My wife noted that she had been using the oven to cook a lot of recipes that call for using the uppermost baking rack (as she was tonight), and that most of these errors seem to be being issued when she is doing that. Are there known issues with having baking pans too near to the oven Temperature Sensor that could be causing the oven to sense that something is in error, and shut the oven off?

Thanks
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
125,433
Location
McMullen Valley, Arizona
My wife noted that she had been using the oven to cook a lot of recipes that call for using the uppermost baking rack (as she was tonight), and that most of these errors seem to be being issued when she is doing that. Are there known issues with having baking pans too near to the oven Temperature Sensor that could be causing the oven to sense that something is in error, and shut the oven off?
I couldn't locate any service bulletins from LG about that, but that does make sense why you are getting that error F18 when using the uppermost baking rack.

Is she ok with using the lower or middle baking rack?

Jake
 

tchp

Premium Member
Joined
Nov 8, 2021
Messages
6
Location
Oregon, USA
We decided to stick with just using the middle rack, but it looks like there probably was no association with the issue being caused by using the top rack of the oven. The oven is issuing the same "F18: An error in the steam generator temperature sensor has been detected" during Pre-Heat, in addition to issuing the error when it has reached temperature. Tonight we have not been able to succeed in Pre-Heating the oven to 425F because the oven issues an F18 error and goes into cooling mode almost as soon as you turn it back on again.

The service tech is coming back next week. He said he would call LG and see if they could offer any insight into this issue. So, hopefully he has a new strategy when he arrives here, as it seems like we are running out of parts to replace. He had said there was a thermistor associated with the Steam cooking function the stove has (we have never used this function), and that it was a part that is probably next in line to be replaced.

The only additional new info is that tonight when we were trying to pre-heat the oven we got a chime and a notification on the touchscreen that said "Press Probe Pad". I can't find anything about that message that explains what it means. We have never used the temperature probe that came with the oven.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
125,433
Location
McMullen Valley, Arizona
The service tech is coming back next week. He said he would call LG and see if they could offer any insight into this issue.
Yes, that's the best thing to do now. I haven't run into this problem or I could tell you what part to replace to fix it.

Let us know what he says.

Jake
 

tchp

Premium Member
Joined
Nov 8, 2021
Messages
6
Location
Oregon, USA
The service tech has still not made it back, as he said the part he needed did not arrive. He said that he spoke to LG's tech people, and they told him that the issue that is causing this problem is a short in the temperature probe jack that is inside the oven. We have never used the temperature meat probe. I did go ahead and plug it in, and removed it, so see if it might correct the presumed short circuit issue that they say is causing the oven to go into cooling mode, but it did not end up helping. Due to the microwave that is mounted on top of the oven, the tech said it might be a lengthy service call to access the oven's internals to replace the part. I am assuming that the part would be a new temperature probe jack. Hopefully, LG is correct, and this is the cause of the issue.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
125,433
Location
McMullen Valley, Arizona
Thanks for the update Thomas!

Jake
 

tchp

Premium Member
Joined
Nov 8, 2021
Messages
6
Location
Oregon, USA
The tech did make it here today to replace the temperature probe jack inside the oven. He found what appeared to be a short between the oven's internal reflective foil insulation and a broken area of fabric insulation tubing on the back of the probe jack. He left feeling pretty confident that the cause of all this trouble had been isolated, and also because the engineer he had spoken to at LG had been pretty confident that the issue would be found to be the probe jack inside the oven. I will update if we experience any further problems with this same issue.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
125,433
Location
McMullen Valley, Arizona
Ok Thomas, sounds good, yes keep us posted.:)

Jake
 
Top