Bradford White 40 gal. gas water heater natural draft about 8 yrs. old.
With the combination of issues listed below would you list this water heater as a serious issue/defect or simply defer it to a plumber for evaluation?
There was so much soot and rust on the top of the burner that it was affecting/obstructing the flame. The flame was blue with some orange. Some of the flame was diverted downward.
I also noticed staining around the exhaust port at the top of the unit just below the vent hood. Never saw this before. I checked the seam (top of the water heater outer shell and heater vent) with a combustible gas detector which indicated the presence of gas/unburnt fuel. Being this seam is right under the vent hood any unburnt gases would still likely go up the vent pipe. I did check around the outside of the hood with a combustible gas meter which didn’t detect anything at the time.
There was also a dark stain in the osb subfloor directly above the water heater (water heater is in the basement). The stain tested 1 to 2% higher than the non stained area when checked with a moisture meter (not sure if this is related).
At the very least I am planning to recommend further evaluation.
Your advice is appreciated!