KitchenAid KFGD500ESS01 - Lower oven smells + high flames, rest of range OK

[aziur]

My SO and I, both DIYers, are stumped with our KitchenAid's lower oven (Double Oven, model KFGD500ESS01, Natural Gas) and are hoping for second thoughts before we throw in the towel and bring in a professional.

tl;dr: Lower oven emitting strong smells (not rotten eggs); flames are also excessively high (blue, occasional yellow tip). New OEM igniter, adjustments to air shutter, and burner tube had no effect. Stovetop and upper oven work as normal.

More detail on what we've done below. We've generally been able to repair the appliances in our home, but KitchenAid has been testing our patience -- and welcome any ideas on fixing the smell and flame issue.

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Both ovens stopped heating a few months ago and found upper and lower oven igniters were faulty (broiler igniter OK), so we replaced them (OEM parts used throughout).

3 weeks later, the lower oven started smelling shortly after turning it on. We ruled out a gas leak since the smell went away when turned off, and the top oven and stovetop were fine.

We replaced the lower igniter again in case the new one was a dud -- didn't work.

Turned it on again and noticed moisture on the stove griddle top, high flames from the oven burner tube, and a lot of soot on the tube and heat shield (pictures linked above).

This seemed like incomplete combustion, but we adjusted the air shutter and swapped the burner tube, but still no effect to the smell or flame.

The oven was here when we moved in and for a NG hookup; we have not made other adjustments to the oven outside the above.

 

Thanks in advance!

[Guest]

Disclaimer:  There are professionals who post here.  I'm like you as far as DIY goes.

I feel like the issue is with the swap of the burner tube and adjusting it.  

It seems like you have said that the oven worked correctly for three weeks after replacing the igniters; is that correct?

To me it seems like the burner tube should not even be adjustable but what do I really know.

Did anything happen between replacing the igniters and three weeks later?  Did you use both flames in those three weeks?

 

[Guest]

I see now in a diagram how the tube is adjustable.  

I say first go back to the original burner tubes. 

Could it be that you have a bad electrical connection on one of the wires going to the igniter?

Seems less likely that its the wiring on the new igniter. 

Last I knew the igniter had to glow to cause the gas valve to open; if there's a short in the wire going to the igniter could it be causing the gas valve to open and close during normal operation and therefore creating a weird air / gas mixture that is causing the smell and moisture.

I would either swap the burner tube back or adjust the new one back to where it was and then look for breaks in the wire that goes to the igniter.  Look from the point it gets power all the way to the igniter.