Most vent free gas log sets will release an initial burn off odor during the first 3 to 4 hours of operation. However, if the set continues to release a noticeable smell when operating, there is likely an issue with log placement. The log placement instructions should be reviewed and a visible check made to ensure that flames are not hitting any of the logs directly. It is also important to service a vent free set on a yearly basis. Accumulation of dust, lint, or pet dander into the assembly can partially clog the air intake, releasing an odor.
on January 7, 2015