Kenmore oven: Inconsistent temperature

[murphycc]

I wonder if somebody could help me troubleshoot my Kenmore range (model 790.96112408)?

The oven heats inconsistently. It does not have a constant temperature offset, rather, I can set it for 400 F and it might be there for a while and then go to 450. I will turn it down to 375 and it will eventually return to 400. But the temperature might be very accurate at 350 F. I am using one of those metal coil thermometers in the oven to measure the temp.

This is a new behavior in the last 6 months or so.

What I have done:
- measured thermal probe to be 1087 ohms
- measured bake element to be 16 ohms
- measured broil element to be 14 ohms

These measurements all seem to be in the acceptable range, based on the service schematic I found in back of oven.

My questions:
- Does anyone know what else could be the problem? Could it be the controller board? How would I know without just having to go out and buy one?
- These measurements (above) were at room temperature, but could they yet be incorrect when the oven is in use?

Thanks for any help. If I call a repair guy and need a controller board, I also have to pay him $100+. If I know it's the controller board, I could just replace it myself.

-Chris

[AJ]

These measurements (above) were at room temperature, but could they yet be incorrect when the oven is in use?

Bingo! That is often what I find is the case. I would start with replacing the oven sensor, part # 316490001

Could it be the controller board? How would I know without just having to go out and buy one?

It could be the control board too. The contacts on the bake relay could be failing. This is something that would be hard to diagnose. Best bet would be to replace the oven sensor first and if it still gives you trouble replace the control board/clock, part # 316557118

Hope that help.

Let us know how it turns out or if you have any other questions.

[murphycc]

Thank you very much! I will try that oven sensor first. Maybe it is marginal at high temperature.

-Chris

[AJ]

Sounds good, let us know how it turns out for you.

[murphycc]

Well, I tried a new oven probe but the temperature inconsistency still persists. I think I will go ahead and order a new timer/control board tomorrow.

-Chris

[JWWebster]

Is this an LG stove? If it is their is a warning out there

[murphycc]

No, this is a Kenmore. I believe it is made by Frigidaire. Model #79096112408

What is the warning regarding the LG ranges?

-Chris

[AJ]

What is the warning regarding the LG ranges?

Just posted about it.
http://appliancejunk.com/forums/index.php?topic=10995.0

I had not seen that yet JW, thanks for pointing it out.

[murphycc]

OK... update.

I have replaced the temp sensor/oven probe with no change in oven behavior.
I then replaced the control board/clock timer and while it seems a little better, I still see the following behavior:

Oven will preheat just fine to 350 and stay there just great
I put in a cookie sheet of cookies and temp stays at 350 for a few minutes... I look again in a few more minutes and it was up to 375-400 or so.
So I opened the door a bit to bring it back down to 350. Sometimes it stays there for a while.

* I am using one of those metal-coil oven thermometers

Questions:
- The thermometer is close to the cookie sheet... do you think that's an issue in giving a false reading? I will try it higher up in oven away from cookie sheet
- Is there a way to clean out the venting system for this oven, or does that never have a problem? Could that contribute to problem?
- Any other suggestions of what could be wrong?? I'm getting nervous with Thanksgiving coming up!

Thanks,
Chris

[murphycc]

I bought a second coil thermometer last night and it seems to be more accurate than first thermometer. Also, I guess temp can vary across the oven. I hung this thermometer right on the oven probe and it seemed to remain pretty accurate.

I will (hopefully) get some final results today as I test the oven again...

[JWWebster]

Ok when do we get some cookies?