As temperatures drop across Chicagoland during the fall and winter months, gas furnaces work around the clock to keep homes warm and comfortable. However, an aging or neglected furnace can pose a serious, unseen hazard: carbon monoxide (CO) leaks.
Often referred to as the “silent killer,” carbon monoxide is a toxic, colorless, and odorless gas produced when fuel does not burn completely. Understanding how gas furnaces operate and recognizing the warning signs of a failing heating system can protect your household and save lives.
How an Aging Furnace Produces Carbon Monoxide
Inside every gas furnace is a component called the heat exchanger. Its job is to separate the dangerous combustion gases (created by burning natural gas) from the clean air circulating through your home’s ductwork.
As furnaces age—typically past the 15 to 20-year mark—several mechanical issues can develop:
- Cracked Heat Exchangers: Years of repeated heating and cooling expansion cause metal fatigue. Microscopic cracks or rust holes can develop, allowing exhaust gases and carbon monoxide to mix directly into the breathing air supplied to your living spaces.
- Improper B-Vent & Roof Flue Exhaust: Blocked, rusted, or improperly sized B-vent chimney flues prevent combustion gases from venting safely through the roof, forcing toxic fumes back down into the home (backdrafting).
- Incomplete Combustion: Dirty burners, clogged orifices, or improper gas pressure cause yellow, unstable flames that generate elevated levels of carbon monoxide instead of clean blue flames.
Symptoms of Carbon Monoxide Exposure
Because carbon monoxide has no smell or taste, mild exposure often mimics the flu. Be alert if occupants experience:
- Frequent headaches, dizziness, or unexplained fatigue
- Nausea or shortness of breath
- Symptoms that improve when leaving the house and return upon returning home
- Pets acting lethargic or unusually sick
Essential Steps to Protect Your Home and Family
1. Install and Test Carbon Monoxide Detectors
Place UL-listed carbon monoxide detectors on every level of your home, especially outside sleeping areas and near the furnace room. Test them monthly and replace battery backups twice a year.
2. Check Your Furnace Flame Color
When inspecting your furnace area, look through the sight glass at the burner flame:
- Blue Flame: Indicates clean, complete, and safe gas combustion.
- Yellow/Orange Flame: Signals incomplete combustion and elevated carbon monoxide production—require immediate professional servicing.
3. Schedule Pre-Purchase & Annual HVAC Safety Evaluations
Never assume an older furnace is safe just because it turns on and produces warm air. During a thorough home inspection, advanced diagnostic tools—such as ambient flue gas analyzers and specialized CO detectors—are used to evaluate furnace combustion safety, draft integrity, and heat exchanger condition.
Ensure Your Heating System Is Safe This Winter
Whether you are buying a home with an older heating unit or maintaining your current property, a professional furnace evaluation provides crucial peace of mind.
Need a comprehensive home safety inspection? Inspect All Home Inspections Inc evaluates heating systems, roof flues, and combustion safety across Schaumburg, Bartlett, and the surrounding Chicagoland area. Contact us today or schedule your inspection online!