Originally Posted by 5picker
Since you say it won't open in heat but does so when cool, I'd be looking for something where the tolerance of the door is too tight when expanded from the heat and has clearance when cool out.
To piggyback off 5picker, I had the same issue with my rig. Turned out the deadbolt was dragging when things got hot and expanded. If your door won't open when locked, take a look at the strike plate and see if you have any wiggle room there. I ended up filing the opening on mine just a touch, and haven't had an issue since. It didn't take much at all, so if you go this route, go slow and don't remove to much material.