Whirlpool WFE540H0AS 0 Oven overtemp issue

[Lost Dog]

Hi there!

Our WFE540H0AS 0 oven has an intermittent issue where the broiler element will turn on during standard bake mode and the oven will continue to heat up.  This has lead to many burned meals!  We can set the temp to 350F and it will act like it's been set to 500F with the broiler element glowing orange.

It only happens occasionally but sometimes it will happen multiple times in a row, or several times in a week, then go back to normal for a few months.  At one point it issued a F3 E2 error (oven temperature too high).

I tested the Oven Sensor (part number WPW10181986) and it seemed to be fine (I read it should read between 900 Ohms and 1200 Ohms).  Could this give a random issue or if it goes bad, does it just go bad?  Should I just replace it?

The stove top has no issues, only the oven.

Thoughts on what to check?

Thank you!

[Vance R]

You can check the oven sensor at different temps to see if is in spec. 

Temp °F . . . . . . . . ohms

32 ± 1.9 . . . . . . . . 1000 ± 4.0

75 ± 2.5 . . . . . . . . .1091 ± 5.3

250 ± 4.4 . . . . . . . 1453 ± 8.9

350 ± 5.4 . . . . . . . .1654 ± 10.8

450 ± 6.9 . . . . . . . .1852 ± 13.5

550 ± 8.2 . . . . . . . .2047 ± 15.8

650 ± 9.6 . . . . . . . . 2237 ± 18.5

900 ± 13.6 . . . . . . . 2697 ± 24.4

Usually sensor just go out of spec and don't change back and forth. 

Your scenario kinda indicate the broil relay is sticking on when hot. Some ovens will use the bake and broil elements in the "bake" mode for more even heat. 

[Lost Dog]

27 minutes ago, Vance R said:

You can check the oven sensor at different temps to see if is in spec. 

(snip)

Usually sensor just go out of spec and don't change back and forth. 

Your scenario kinda indicate the broil relay is sticking on when hot. Some ovens will use the bake and broil elements in the "bake" mode for more even heat. 

Interesting...  I'll give it a test at different temperatures and see what it comes out to.  I do know that when the oven was in the ~350 range it was reading around 1300.

How do I test or trouble shoot the broiler relay sticking?  Can that be intermittent?

[Lost Dog]

Well, quick update on this...  Thanks for the idea of the stuck relay.  I think that is the issue.

I entered the Diagnostics Mode and tested the broiler relay.  Pressing "Broil" triggers the Broil relay and I confirmed it turned on.  I then pressed "Broil" again to turn it off, and it stayed on.  I had to exit Diagnostics Mode to shut off the broiler.

I then entered Diagnostics Mode again, and the broiler turned on without me triggering the Broil relay.

A new control board is in the ~$400 range, but I found this video on replacing the relays.  If I can find the correct ones, I think I'll give it a go... I've done a bit of soldering and I figure it's either a new oven or control board if I mess it up or not!

 

[Vance R]

Didn't watch too much of the video, the relay has the part number printed on the cover. 

[Lost Dog]

6 hours ago, Vance R said:

Didn't watch too much of the video, the relay has the part number printed on the cover. 

Yes, I pulled my board and ordered two relays ($4.00 each plush shipping).  The video was to show others who may have the same issue a potential solution.  Once the relays are here I'll post an update if it fixed the problem.

[Lost Dog]

Update for those who may find this in the future....

Got the parts today and made the swap.  Pretty simple, even for a novice solderer.  I replaced both the bake and broil in about 20 minutes.  If I had better de-solder equipment it would have gone much faster.

All tests passed... Both bake and broil were tested and they functioned as needed.  The oven came up to 350F without overshooting and the broil element didn't lock on.

I think this did it!  $8 in relays and 30 minutes of my time beats a $400 controller board!

[Vance R]

With that kind of savings treat yourself to a nice dinner.