KERS807SSS05 Range intermittently not heating

[CrazyCarl]

So been working on this KitchenAid range and the customers keep having trouble where it just stops heating. Most recently cooked muffins, worked great. Two days later they tried cookies, it preheated properly and then the temperature just kept dropping after that. 30 mins in and the cookies weren’t done. I’ve verified that bake and broil elements work properly, took the back off and put my amp clamp and got about 8 amps on the bake and the same on each leg of the broil. Temperature probe is in spec and reads the same as my thermocouple. Terminal block connections are good and we’re not dropping voltage under load (checked with LoZ function on my meter). I’m really stumped lol. Any thoughts?

[EngineeredAppliance]

Have you tried to look for error codes via diagnostic mode? Also you say it matches your thermocouple likely at 350F but have you tried various temp ranges: 425, 450. 500 etc? The temp sensors can fail at various ranges. However it sounds like you have an issue with the control board. Don’t see any TSB’s for this. 

[EngineeredAppliance]

Have you tried to look for error codes via diagnostic mode? Also you say it matches your thermocouple likely at 350F but have you tried various temp ranges: 425, 450. 500 etc? The temp sensors can fail at various ranges. However it sounds like you have an issue with the control board. Don’t see any TSB’s for this. 

[EngineeredAppliance]

Have you tried to look for error codes via diagnostic mode? Also you say it matches your thermocouple likely at 350F but have you tried various temp ranges: 425, 450. 500 etc? The temp sensors can fail at various ranges. However it sounds like you have an issue with the control board. Don’t see any TSB’s for this. 

[CrazyCarl]

Only error code was for a stuck key, and forgot to mention I have already replaced the control cause I came to the conclusion that it’s all it could be since all the elements were working. It’s a puzzler. I called tech line and got sent up to a master tech, he suggested might be losing the L2 randomly. I told them to check the cooktop operation the next time it acts up to see if the L2 is dropping out. 

[Budget Appliance Repair]

12 hours ago, CrazyCarl said:

I’ve verified that bake and broil elements work properly, took the back off and put my amp clamp and got about 8 amps on the bake and the same on each leg of the broil.

This doesn't sound right, 8 amps seems to be only about half of what it should be.

Was either the bake or broil element glowing red when you were  getting 8 amps?

[CrazyCarl]

On 6/21/2022 at 7:48 AM, Budget Appliance Repair said:

This doesn't sound right, 8 amps seems to be only about half of what it should be.

Was either the bake or broil element glowing red when you were  getting 8 amps?

It’s a 2000 watt element so 8 amps checks out at 240vac I think. It’s also a hidden bake so I couldn’t see it and I didn’t visually check the broil element, however the oven preheated in 10-15 minutes which is fairly normal for a hidden bake element 

[Microns]

YHou may want to check the relay board, The relays can stich sometimes.

 

 

 

Michael

[Budget Appliance Repair]

23 hours ago, CrazyCarl said:

It’s a 2000 watt element so 8 amps checks out at 240vac I think.

It does check out - Only could find one picture that you could make out the watts and it appears as you said, 2000 Watt @ 240 Vac = 8.33 Amps.

And, YES, for a hidden bake element and only 2000 Watts, I would say preheating in 10-15 minutes is well within normal.