I have a Jotul Firelight 12 that I purchased last year used from a fellow who didn't know anything about it cause it came with the house he bought and he never use it. In fact he thought it was the Firelight 600 and didn't know it was catalytic. So last year we burned it (don't laugh) without knowing it was catalytic - with the bypass damper open just by chance. We heat our home with it so it runs all winter. Now I've put in a new catalyst from Condor - the old one looked okay to my untrained eye but whenever I closed the bypass damper the fire burned down immediately. I also bought a catalyst thermometer from Condor. I was sent the thermometer Condor recommended for my stove but when it arrived the probe was much shorter than the recommended 3 1/2 inches. The thermometer wouldn't register temperature at all either - no matter how hot the stove was. I assumed the probe was too short so Condor sent me their 6 inch probe and said to cut it down to size. I did that. And still the thermometer doesn't register temperature at all. The local Jotul stove shop tells me both the thermometers must be broken (they also told me I should buy a new stove when I told them what model I had). Any other thoughts out there? Thanks for helping! I've learned so much about my stove from this forum already.