So thanks to the awesomeness of this site I recently replaced a vent limit switch and our heater was back in business for a few days. Yesterday I noticed smoke. Removed the door and of course something was on the burners.. After cooling and looking around I realized it was a decent sized piece of insulation. Looking around the heater I also noticed the back upper portion was discolored. I managed to get the insulation off the burners and ran the heater again. The upper back of the heater was hot, but nothing else seemed to get excessively hot. So I have 2 questions, 1. is it crazy to run the heater like this temporarily ? 2. I'm fairly handy is it crazy to try to replace the combustion chamber ? Or are there other options ? Should I just bite the bullet and get a new heater ;-( ? . The manufacture only gave me the whole chamber part ( they don't appear to like discussing things with home owners) and the closest shop wants over 200$/hr to diagnose. Any suggestions would be greatly appreciated. Oh yea it's a Jandy LRZ400EN.