Technical directory · Safety
Soot around furnace
Soot or scorch marks may indicate abnormal combustion or venting and need investigation.
What to observe
Document location and extent without wiping away evidence before an assessment.
A field example
Black residue by a vent or burner opening should be photographed before cleaning. Its position can help a qualified professional trace venting or combustion trouble; wiping it first removes that clue.
What the written work should say
Arrange an urgent registered gas contractor inspection; keep the system off if advised or if alarms sound.
Where this task stops
Cosmetic soot removal can conceal a continuing fault.