Home emergency playbook
Carbon monoxide alarm is sounding
Conservative first steps for homeowners before cleanup, repair, or contractor dispatch. When safety is uncertain, leave and call first.
Immediate steps
- Evacuate everyone from the affected area and call 911 from a safe location before cleanup or repair.
- Move to fresh air and do a head count, including anyone sleeping, bathing, or in an attached garage.
- Tell dispatch if anyone has headache, dizziness, nausea, confusion, chest pain, or flu-like symptoms.
- Wait for responders to measure carbon monoxide before opening appliances, relighting pilots, or going back inside.
Do not do this
- Do not re-enter the building until emergency responders or the utility says it is safe.
- Do not remove batteries, unplug hardwired alarms, or assume a chirp means the danger is false.
- Do not run a car, generator, grill, or fuel heater in a garage, porch, or near open windows.
Who to call
- Call 911 first for immediate danger, injury, fire, smoke, shock, collapse risk, or trapped people.
- Call the utility emergency line before private repair when gas, electric service, public water, sewer main, or buried lines may be involved.
- Call an HVAC contractor for combustion, heating, cooling, boiler, or ventilation diagnosis after immediate hazards are controlled.
Damage mitigation
- After clearance, write down which alarm sounded, its location, age, and whether other alarms followed.
- Have combustion appliances and vent connectors inspected before they are returned to service.
- Replace alarms that are past their date or were contaminated by smoke, moisture, or construction dust.
Prevention
- Install listed CO alarms on every level and outside sleeping areas, with battery backup where needed.
- Service fuel-burning appliances and verify venting before heating season.
- Keep generators, grills, and portable fuel heaters outdoors and far from openings.
Typical cost band
Emergency response is public-safety driven; HVAC or gas-appliance repair can be moderate to high depending on the failed source.
Insurance note
Medical response, appliance repair, and smoke or fire damage may be handled separately; keep fire department readings and HVAC findings.
Related ProFix resources
HVAC Technician emergency guideTrade-specific dispatch, utility-first, and after-hours cost guidance.Troubleshooting encyclopediaSymptoms, maintenance intervals, contracts, and warranty norms.National FAQHiring, licensing, scams, permits, and DIY boundaries.Cost calculatorPlan the permanent repair after the emergency is controlled.