Just a note. Didn't see much on this here doing a search. I had some wood that burned slow and left stuff on the glass window. Some looked pretty tacky. Someone recommended (several videos also on YouTube) cleaning the window by dipping crumbled newspaper in some water, then ash, and gently rubbing the glass. Then rinsing off with just paper and water. My stove's manual simply says to use ceramic glass cleaner. I had it already to clean the top of my stove stove, and it worked excellently on the wood stove's glass.