This afternoon I just couldn't get my woodburner to burn due to the lack of drawing. Usually, as soon as I close the door the fire just roars up the chimney but today nothing and the fire would burn some of the paper then die. After many attempts of adding paper adding firelighters etc I had to give up as I had to go out. On coming back to a then cold house I started from scratch building up the fire with exactly the same kind of paper, kindling, and same wood and now it's away. Why does it do this? This isn't the first time I might add but it's very rare it happens.