After producing a nice bed of coals which mainly consisted of ash and oak.. I decided for the first time to use the front doors on my Jotul F600. Until now I just use the side door.....just easier. I went ahead and place one HUGE piece of blak locust. This must a weighed 20-25lbs and it took a steady 2-hand approach. Opened the damper all the way for the first hour or so and then slowly backed it down to about 3. Put it in around 6:30pm and when I got up at 5am.....still glowing in the center of the stove! I was amazed. One piece went that long. Living room was at 78F. Upstairs at 74F & far family room at 71F. I have 3 more of those massive pieces and then about a face cord of it split. If I would have known that about black locust.. I don't think I would have split any of it. Oh ya...one more thing I noticed..went outside real quick to throw out some trash....black locust stinks to high heaven,,,Wow!