Replaced the sensor and bottom heating element just to be safe. The sensor can be changed from the front, the heating element requires you to move the oven out of the wall. There are clips you need to hold down when installing the heating elements but otherwise it's pretty straightforward. The oven no longer stops at 285 but it's still about 25 degrees lower than the setting. This is ok as long as it's consistent and it has been. Think maybe a circuit board needs changed but these replacements at least allow us to use this $1800 oven.