We moved into a new home with a heat and glow vented fireplace which gives off an odor tha tburns the throat and irritates the tongue every time we use it. They have changed the screen checked behind the box with a scope and reducd the level of gas coming in. could the logs be causing the problem? Do you have any ideas?

NO but I would get a CO test in the area around the unit and I would not fire the unit until it is fixed.

The insert is equipped with a fan, right? Check for evidence of some type of chemical spill on the enclosure (grout sealer, etc.) that may be burning off when the unit is hot. Some construction workers are so clumsy...