Kitchenaid KEMS308SSS02 Oven/Microwave- No heat in all lower oven elements

[kcstueber]

Hi all,

I'm hoping one of you can guide me along with the information I have collected so far.

1. The original problem was the outer broil element wasn't heating. This unit has an outer broil and inner broil elements
2. I removed the broil elements for testing and indeed the outer was open/failed
3. I must have installed it incorrectly and one of the terminals must've been touching the chassis because as soon as I tested the broil operation, the circuit breaker tripped.
4. I uninstalled/reinstalled the broil elements again, being much more careful, put power back, but now all lower oven elements won't heat.
5. Control panel appears to be operating normally, convect fan operates, lights operate, microwave operates. When entering a setting, all appears normal, except no heat.
6. I've checked line voltage on both legs.
7. All of the elements have the correct resistance values, except the failed outer broil element.
8. There is 0.0V across all of the element terminals when powered on each element.
9. The temperature sensor checks good, the large fuse on the control board is good, and the oven shutdown thermal cutoff has voltage on both sides.

I'm thinking I damaged the control board, but I'd like to verify that before ordering it. What I'm not sure of is how to verify that. I've got the tech sheet, and have a reasonable understanding of electronics. Thanks very much for the help.

Kurt

[Terry Carmen]

> 8. There is 0.0V across all of the element terminals when powered on each element.

If you do not have 240 volts between T3-3 (Red) and T1-1 while in bake, it means you blew up one or more relays on the Appliance Manager board.

[kcstueber]

Hi Terry,

Thanks for the reply. I've been double checking my voltages with some additional testing. I was mistaken about my testing of the thermal cutoff switch. If I probe one side of it I get 240V, the other side 38V. That doesn't sound right. Isn't this a normally closed switch unless failed, then is open? Looking at the schematic, this would seem to cause an issue with voltage at T1. Does it make sense that a dead short could damage this switch?

I'll also check for 240 per your recommendation. When I probe between these, I get .001-.004V, but I'm concerned about my finding above.

Thanks for such a quick response.

Kurt

[kcstueber]

Hi Terry,

 

Indeed, the thermal fuse is open. I have just tested it with wires disconnected. Would it be reasonable to verify if this resolves all issues by directly connecting both sides and checking for heat? Of course, I would order a new fuse immediately.

Thanks,
Kurt

[isaac]

1 hour ago, kcstueber said:

Would it be reasonable to verify if this resolves all issues by directly connecting both sides and checking for heat?

Sure,  just for testing,  

[kcstueber]

Thanks Issac,

 I did do this, and luckily everything checks out and heats. One question is the faulty broil element. It'll take a few days to get it. I don't want to take a chance with a problem. If I disconnect the leads from it, insulate them, I'm guessing that it will eliminate any issues in case someone turns on broil.

Kurt

[isaac]

Yes,  but i wouldn't use that portion of the oven,  when you select any cycle it would use broil for pre heat,  also is the insulator heat resistant?  Avoid using the lower oven at all,  good luck

[kcstueber]

Good points. My thought was disconnecting the leads from the back, so the element would still be in place. The insulated wire connectors would be in the back of the oven. it's a pain in the kitchen to have the oven out of it's cavity, but either way, I'm having to put it in and out.

I'll see if I can fast track the new element.

Thanks.

 

[isaac]

I guess leaving out the wire on the limiter should cut power to that portion as you experienced,  perhaps thats the route to go

[Natosha Jacobs]

I think your oven heating elements is defective. When an oven won't heat, the most likely problem is a defective heating element. An electric oven has two elements, one on the top for baking and one on the bottom for broiling. It's easy to tell when an element is burning out or not working: A functioning element glows bright red. If your oven is warm, but not the correct temperature then:

1. Check the heating element you want to use. Sometimes when an oven is set at "prebake," both heating elements turn on. It's possible that one element is working and the other is not.

2. If one element isn't working, you will need to replace it.

3. If you install a new element and the oven still doesn't work, you may have an electrical issue. This is where your voltage meter will come in play. You will need to test the wires that lead to the heating element hook-up to the heating element. There could be a bad wire or loose connection that is causing your element to not work. See the illustration below for details about where to aim the voltage meter.