I am having a problem with my gas fireplace, when the unit is first turned on there is a strong odor that lasts about 10-15 minutes. I am using a Fireplace Extrordinair unit. The odor is so strong I have to open the windows to air out the house while it is starting. We've had the dealer to our house too, and they have continued to say that it is a "dust" burn-off, but we do not agree. We never had this problem for the first two seasons of using the unit, it just started happening in the third season. Additionally, we have had the unit cleaned numerous times, and it is DUST free at this point, yet there is still an odor. We have confirmed that it is NOT gas, but are still concerned something else on the unit is emitting a harmless odor. Does this sound similar to your problem - or is anyone else who posted to this original note familiar with a similar problem?