Why is my GE oven covered in white powder after a cleaning cycle?

That white powder is exactly what you suspected: your silicone bumpers didn't just melt, they oxidized into **silicon dioxide** ash. While silicone is great for standard baking temperatures, a GE self-cleaning cycle usally ramps up to anywhere between 800 and 1,000 degrees Fahrenheit. That is way past the breakdown point of even high-quality silicone. They basically underwent a chemical reaction and turned into a fine mineral dust that is now coating every square inch of the porcelain.

You haven't ruined the oven, but you do need to be careful with the cleanup. Don't grab the shop vac unless you have a high-end HEPA filter, or you'll just blow that fine dust all over your kitchen. The best way to handle this is to wear an N95 mask and use a pile of damp microfiber cloths. You want to trap the dust, not kick it up into the air. Wipe down the walls, the floor, the ceiling, and expecially the fan area if yours is a convection model. As for the racks, they are probaly the biggest casualty here. GE usually tells you to take the racks out during a clean cycle anyway becuase the high heat ruins the finish and makes them incredibly difficult to slide. Since they were in there with the silicone, they might have some permanent discoloration or a gritty texture. Give them a good scrub with a heavy-duty scouring pad and some Barkeepers Friend to see if they can be saved.

Once everything is wiped clean and you can't see any more white residue, the oven is safe to use again. I usually recommend running it at 400 degrees for about thirty minutes with nothing inside just to be sure any remaining microscopic particles are settled or scorched off before you put food in there. It might smell a bit like hot dust for a minute, but it's not going to poison your next meal.

That's wild that it just turns into ash. I’m a total newbie with these high-tech ovens and honestly, the manual makes the self-clean sound so easy, but stories like this make me nervous.

Quick question though—does that dust get into the door gasket? I’m worried that scrubbing the seal might tear it or make it lose its shape. shold I just use a soft toothbrush on the rubbery parts or is that overkill? I'd hate to fix the dust problem only to end up with a heat leak.

Be super careful with that door gasket. If it's the braided fiberglass type, scrubbing it with a toothbrush will just fray the fibers and ruin your heat seal. I ussually just use a damp cloth to blot it gently. Also, definitly pop off the convection fan cover if your GE has one. That ash loves to settle inside the fan housing. If you don't get it out now, the fan will just circulate that dust onto your food the next time you use the convection setting. It’s a tedious job, but skipping that step usually leads to a 'dusty' smell every time you cook.

Don't forget to unscrew the glass light cover and clean the inside of that too. If that ash gets stuck between the bulb and the cover, it can actualy bake onto the glass next time you use the light and make it super dim. I'd also check the vent at the back of the cooktop. If yours vents upwards, you might find some of that white residue settling on your wall or the underside of your microwave. It's crazy how far that fine dust can travel when it's basicly smoke.

One thing people usally miss is the temprature sensor—that little metal probe near the top back corner. If that thing is coated in ash, it won't read the heat correctly becasue the dust acts like an insulator. I’ve seen GE units start swinging 50 degrees off-target just because the probe was dirty.

Give it a gentle wipe with a dry microfiber, but be careful not to bend it. You want it clean so your bake times don't get all wonky. Also, peek at the door latch assembly. If that white powder got into the locking mechanism, it might get sticky or throw an error code later on.