What should I document for combustion or carbon-monoxide warning? Treat alarms, symptoms, soot, spillage or fuel odor as urgent safety signals and follow emergency and appliance guidance.
What to compare
Record the first location, timing, trigger, recent change and an unaffected comparison area. Keep weather, occupancy and system state with every photograph or reading.
What the evidence cannot prove alone
A single reading, image, smell or temporary improvement cannot certify a concealed source. Keep at least two plausible pathways visible until repeatable evidence separates them.
Safe next step
Stop and use qualified help when the checklist reaches energized water, combustion danger, sewage, unstable materials, unsafe access, rapidly worsening damage or acute symptoms. Continue with For combustion or carbon-monoxide warning for a bounded action, stop rule and professional handoff route.
