Kitchenaid KEBS209BSS01 temperature is off

[skippy129]

I have double convect wall oven that is not maintaining the correct temp in either the top or the bottom.  However, the problem is manifesting itself same in top and bottom. There are no error codes. I have ohmed out the temp sensors and all three coils in both ovens and all are in spec at room temperature.  I have placed the oven in diagnostic mode and cycled all the relays to make sure the correct elements come on at the right time (and only the command one comes on - e.g not bake & convect at the same time). To confirm the actual oven temp, I used an external digital oven probe with SST braided cable thermocouple (that I usually use for my outdoor smoker) placed in the middle of the oven on a rack.

Top oven test: Top oven set to bake @ 350, Bottom oven off and at room temp.

Top oven goes to "preheating" and temp slowly climbs on the oven display and the external probe.  During preheating, the oven display and external probe stay with 5 degrees of each other. Once at 350, the oven display beeps and locks in at 350 (normal). The external probe continues to climb to about 400 and then starts dropping back to about 340.  The temp on the probe then climbs back to 400 and the cycle repeats.

Bottom oven test: Bottom oven set to bake @ 350, top oven off and at room temp.

Bottom oven goes to "preheating" and temp slowly climbs on the oven display and the external probe.  During preheating, the oven display and external probe stay with 5 degrees of each other. Once at 350, the oven display beeps and locks in at 350 (normal). The external probe continues to climb to about 375 and stays there cycling back at forth from 370-380.

I thought the bottom oven was just out of calibration. So I turned it off, let it cool down significantly (to around 200) and changed the bottom calibration to -20 and repeated the test.  All functioned as before but this time it maintained temp around 400. I thought I just calibrated the wrong way, so I repeated the test with calibration set at +20. This time it maintained temp at around 425.   

 

[Aapltech]

Skippy129- all (almost,except for a very few high end units) operate in a way you may not be familiar with. all ovens both gas and electric will heat 30-50 degrees on average over set temp, then cycle off and cycle to 30-50 below set temp. This cycle continues constantly throughout cycle. when testing for proper heat you can watch these cycles over 4-5 cycles minimum and calculate average in order to test for proper temp. On newer ovens, wall and otherwise, it is extremely important that the customer allows for a proper preheat of 15-20 mins beyond the "beep" heard when preheating. If you were able to see the temps throughout cavity when the unit triggers off for preheat the cavity would have high and low temp spots due to insulation properties, vent off location and oven sensor location. If the customer allows for a proper preheat and cavity stabilization they will have drastically improved baking results. 

 I have been in the industry over 15 years and have run many many calls where the only problem is improper preheat. This comes down to customer education at the sales level and in the field on a tech level. Manufacturers do this for  variety of reasons, one of which includes advertising a fast preheat time.

If you are using a thermocouple on a meter you can reduce these swings and get a little better sense of the temp that is affecting food by using a loaded meter, or adding a large ball of tinfoil on end of the probe to reduce the swings, but from a tech perspective the swings in heat tell the whole story!!

Hope this helps!

 

[Hiroshi]

Have you noticed some problem with your baking? It may sound funny, but I have had many suspected heating problems proven to be a non-issue by baking a sheet of diagnostic crescent rolls... if they are flaky and golden brown in the allotted time, all is well.

+plus you get to eat on the job...

 

[16345Ed]

Sounds like normal oven cycling.

 

Watch out for aluminum  foil!

had a customer complaint about uneven heat not getting to temp etc on electric oven. (Hidden bake element)

I took aluminum drip trays out of bottom of oven and she worked perfect.