we bought our home new about 2 years ago and the first time we used the fire place the house got filled with smoke. it did not happen immediately, but over a few hours. the builder said to crck a window to allow the fire place to draft right bacause some new homes are built very tight. even though that sounded silly, we did it and we still go the smoke and the house was colder. if you look closely when a fire is burning you can see a small amount of smoke leaking in at the top of the fan grill. any ideas?