Carbon monoxide (CO) is odorless, colorless, and potentially deadly. Understanding the risks and prevention measures protects your family.
What Is Carbon Monoxide?
CO forms when fuels (gas, oil, wood, charcoal) burn incompletely. Common household sources include:
- Gas furnaces and water heaters
- Gas stoves and ovens
- Fireplaces and wood stoves
- Attached garages (car exhaust)
- Generators
- Gas dryers
Why It's Dangerous
CO binds to hemoglobin 200 times more readily than oxygen. When you breathe it, your blood can't carry oxygen to vital organs.
Symptoms of CO poisoning: - Headache - Dizziness - Nausea - Confusion - Weakness - Chest pain
Symptoms are often mistaken for flu. The key difference: CO symptoms improve when you leave the house.
HVAC-Related Risks
Cracked Heat Exchangers The heat exchanger separates combustion gases from your home's air. Cracks allow CO to enter your living space. Warning signs:
- Yellow or flickering pilot flame (should be blue)
- Soot around the furnace
- Excess condensation on windows during heating
- Visible cracks or rust on the heat exchanger
Blocked Flues Flues vent combustion gases outside. Blockages from debris, animal nests, or collapsed sections trap CO inside.
Backdrafting When exhaust fans or other appliances create negative pressure, combustion gases can be pulled back into the home instead of venting outside.
Prevention Measures
1. Install CO Detectors California law requires CO detectors in homes with gas appliances or attached garages.
- Install on every level and near sleeping areas
- Replace batteries annually
- Replace detectors every 5-7 years
2. Annual HVAC Maintenance Professional maintenance includes: - Heat exchanger inspection - Combustion analysis - Flue inspection - Safety control testing
3. Proper Ventilation - Never block furnace air intakes - Keep flues clear and inspect annually - Ensure adequate combustion air
4. Safe Practices - Never use generators, grills, or camp stoves indoors - Don't warm up cars in attached garages - Never use the oven or stove for heating
If Your CO Detector Alarms
- Don't ignore it - even if no one feels symptoms
- Open doors and windows for ventilation
- Turn off gas appliances if safe to do so
- Evacuate everyone including pets
- Call 911 from outside
- Don't re-enter until emergency services clear the home
After a CO Incident
Have your HVAC system inspected before using it again. A qualified technician can identify the source and make necessary repairs.
CO safety is not something to neglect. The combination of working detectors and regular maintenance virtually eliminates the risk.