What this usually means
Carbon monoxide has no color or odor. Never use smell alone to judge safety, and do not ignore an alarm or symptoms such as headache, dizziness or nausea.
Leave the building, contact emergency services or the gas utility as appropriate, and do not restart suspected equipment until it is evaluated.
What you can safely check
- Working carbon-monoxide alarms
- No blocked vent termination
- No soot or visible combustion damage
- Annual equipment-appropriate safety review
When to call a professional
Treat any carbon-monoxide alarm or suspected exposure as an emergency; leave immediately and follow emergency-authority guidance.
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