Empire DV-215 Direct Vent Natural Gas Heater "old gas heater burning soot" Questions

...old propane fireplace and today when I was checking the propane tanks level I noticed that the fireplace vent has a black soot above it. What could be causing this? burners burning yellow , in ...

...old school (30yr approx) vulcan gas heater works brilliantly but the glass has gotten very sooty (blackened) can I dismantle to clean & how?? if the glass is sooty then cleaning it will not solve ...

...old is the Thermo-couple?-- and is it dirty from soot build up?-- It can be polished-- that might help. 3.) THe Pilot flame needs to be just slightly in the path of the flame, so that it generates ...

...orifice. The gas/air mix has to be close or the nasty yellow smutty stuff happens. The gas valve needs to be set for LP gas pressure and the pilot orifices need to be changed. Nothing to it old