I have been burning wood in my Avalon Olympic for the last three years and the glass is getting fine scratches and almost has a fogged look on part of the glass. It doesn't matter what I do I can't seem to get the glass to look clear again. Does the glass go bad in the time of three years? I would hope it would last longer than this. It drives me crazy not to be able to see the flames clearly. What could or should I do?