In this case you can see gas fireplace charring - make no adjustment to your screen. This is gas fireplace charring in the extreme.
What you see is what you get.
This charring could have started a long time ago.
Or maybe it is recent.
It appears old to me. The charring extends up and onto the roof shingles and deck wood framing.
This unit needs an adjustment.
This fireplace is creating too much carbon in the gas/air mix. And maybe from day one. Why?
Because the ceramic logs are similarly charred.
My gas fireplace, adjusted properly from the beginning, and used very regularly since, has NO such charring on the ceramic logs. Or outdoors on our siding.
It is 15 years old.
This fireplace seems to be used regularly as well. It is 19 years old.
Certainly, some professional care is in order.
My recommendation: look at your house. Things often give evidence of stress or a need for service. This charring is such evidence here. While you don't need to adjust your screen, these folks do need to adjust their fireplace!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560