Moisture forms on the oven door window.
Do not attempt service or replace parts of the appliance unless referred to in the owner's manual. Follow all safety precautions provided in the owner's manual.
Oven condensation is due to heat being applied to a cool interior. To help prevent this, we recommend the following:  

  1. Open the oven door(s) to the first intermediate stop during preheat.  
     
  2. Leave the door(s) open for several minutes to allow the moisture to disperse.  
     
  3. Close the door(s) and continue as usual.