Loaded up my Jotul F400 this morning, waited about 30 minutes for it to get going. Not much was happening so I open the door to take a peak. After I closed the door about 15 seconds later I heard a boom, then a puff of smoke came out the back. Fire started to burn and the stove was burning normal. This is the first time this has happen (scared the **** out of me at 3 AM :bug: ). Can anyone please explain what happen.