One good thing about replacing GE with GE is the fit guarantee.

specific info on Fit guarantee: “

“The GE Appliances Fit Guarantee covers modifications to your existing cabinet and is not valid for new cabinet installations related to new home construction or remodeling. In unusual circumstances, the $300 maximum allowance may not cover the full cost of fitting your new 27" or 30" built-in wall oven into your existing cabinet; you are solely responsible for all costs that exceed the $300 maximum cabinet modification allowance. GE Appliances makes no other guarantees as to the proper fit of your new built-in wall oven other than as set forth herein”

Replace the motherboard before you spend 4K on anything new.

Did service actually check it, or were you told by phone that it's a goner without a diagnosis of what exactly is wrong?

Your model number ZET2PLSS does not search for parts ... but ZET2PL1SS
does. Majority of parts are available, although a particular circuit
board is not.

The problem would have to be something in common to both ovens since they're both exhibiting the same symptom of overheating. Are you sure both are overheating, or did one overheat and cause the whole thing to get excessively hot?

There are three common boards. One is the entire control panel. One is the display board, the other is a power supply board. The power supply board is the one that's NLA.

Each oven cavity has a separate relay board that operates power to the various heating elements. I would think a stuck relay (causing an element to stay on continuously) is implicated in an overheating situation but seems unlikely both of those boards would go bad at the same time ... which is why I ask if maybe only one of the two ovens is overheating.

Note that your rotary knobs are selectors for the electronic control board. It has electronic sensors for temperature control, not old-style thermostats. Each oven cavity has a separate mode selector, temp "encoder," and temp sensor (which is only $15-ish) but also seems unlikely the affected item(s) would fail simultaneously on both.

Shoot. I ended up making several trips to the appliance store and pulled the trigger on new Monograms before the above comments were written about investigating what's wrong before I replace them. However, between your thoughts, dadoes and Greendesigns, and a conversation with my engineer cousin yesterday who told me he always replaces cheap parts on appliances himself in order to buy time, I am regretting just listening to the service department's thoughts about "not worth it" before I even had someone come out to see. Ugh.

It was definitely both ovens because I tried them separately, they heated up crazy-like, and after I tried the "turn the circuit breaker off " trick and restarted them, smoke started pouring out of each one and I got nervous about an electrical fire, or something. It felt scary.

I guess my thinking on the purchase was, when I heard the cost of having a guy come out, $90 to walk in the door and then some amount I forget per 15 min, plus parts if they are even available, and then reading on here of the many, many tales of appliance early death, I got discouraged and just went with new. Felt like "good money after bad" kind of thing.

But OF COURSE it is not in the interest of the appliance store to encourage you to repair instead of buy new. I need to find a good repairman not associated with a store.

I bought new Monograms for the same reasons I had bought the old ones, the knobs, the rolling racks (2 each now, not 3 each). I considered the GE Cafe French doors model cause I thought the doors look cool and might be cool to use (I am not short and have never had trouble getting things in and out of a traditional oven.), but then I reasoned that I'd be paying basically the same amount (about $5300-$5600) for the French doors on a supposedly lesser model GE. It could well be that the "innards" of the Cafe, Profile and Monogram are EXACTLY THE SAME and I was just fooled into thinking there is something higher quality about the Monograms by the higher price tag. Count me among the suckers if that is nonsense. They get installed Monday. Hope they work well and last long.....

Thank you all very much for taking the time to share your thoughts.

Bosch rolling racks are in the $300 range. a better deal