Yes you can!...loaded this morning from a cold start...cracked the side door 1/4 " like usual until the wood gets totally involved...leaned down to shut the door and heard a slight whistling sound near the top corner of the door...ran my thumb around the door checking for a leak but the sound continued...moving my thumb above the top of door near the right front corner and the sound stopped...(see photo)...there's a small decorative gap in the casting from the top of the stove to the door that's about 1/4" wide...struck a match and slid the flame along the gap and the air would suck the flame toward the stove and would blow the flame out...I decided on a quick fix and stuffed an old piece of door gasket in the gap to plug the leak...must have been leaking since I got the stove in August because the primary air is bit more sensitive now...I'll have to check on the inside when I get time and see what's going on...maybe some missing stove cement?...Are there any other F600 owners that have found any air leaks?