Hello all! We have an 18 month old HBL8450 from Bosch that we’ve been struggling with forever. We finally figured out though the use of two oven thermometers (two brands) that there is some strange behavior that has been causing us to have to alter cook times. For things like cakes, the heating characteristics are especially troublesome.

The oven preheats properly and accurately, lets say to 350. This takes about 15m from “cold.”

• Temperature drops drastically when food goes in. Okay.
  
• However far the temperature dips—can be 25, 30 degrees—it stays put
  
• After around 12 minutes in, the temperature begins to rise
  
• 15m in we are finally at the proper temperature. Food has spent most of that time under temp.
  
• After another 10-15m the temperature begins to rise and will far exceed the set temp. But then the food is done.
  

It’s almost as though in that first 10-12 minutes the oven either doesn’t try to resolve the temperature or it tries and fails. Most baked goods will bake 20-30 minutes which means that it doesn’t even “average” to the correct temperature. I set a 12 degree offset and it yields better results, but it just feels wrong, like a poor hack of the oven. I’ve even tried playing games like preheat a little higher so it drops to the right temp and then turning off and hen on the oven to the right temperature. That works until around 12 minutes in and then the temperature DROPS below set...even with the offset. Again, it feels like the oven is confused about what the right thing to do is.

My wife has suggested this may all be normal since on a very long cook, for like a roast, it probably evens out. Who makes roasts on a daily basis? :)

Any insights are appreciated. We have a repair guy coming and we don’t want to pay him $130 to tell us that’s just how it works. :(. I’d rather fix it myself with parts if we can narrow it down.

Edited by user Monday, February 15, 2021 7:30:32 AM(UTC)  | Reason: Not specified