I recently installed a zero clearance wood burning fireplace with the help of my neighbor, who has done his own install and a couple of other friends/family. Everything went smooth, but as I started looking again at the installation manual, we installed it about 2 inches too far back, so I need to push it forward two inches. The only thing I am concerned with is the chimney, there are two 15 degree elbows,( I have the super pro class "A" chimney pipe, the top has locking threads but the bottom of it does not it can rotate freely). I was thinking of loosening the claps on both and slowly pushing it forward, but I am worried about the fire stop and flashing at the roof getting damaged. I have plenty of slack for the electrical and fresh air hose and there are no other concerns except the ones I listed. Any advice would be gladly accepted.