Technical directory · Safety
Carbon monoxide alarm event
A sounding CO alarm is an emergency signal, not a prompt for a cleaning estimate.
What to observe
Leave the building, call 911 or the local fire service from outside, and follow responder instructions.
A field example
A sounding alarm is actionable even when no odour is present because CO cannot be sensed by smell. Leave and contact responders outside; preserve their findings for the registered contractor who later evaluates the appliance.
What the written work should say
Keep the furnace off until qualified inspection determines the source and safe return to service.
Where this task stops
Do not silence an alarm and schedule a routine cleaning as the response.