Your furnace’s heat exchanger is one of the most critical components of your heating system. It transfers heat from the burner to the air that warms your home while keeping combustion gases separate from the indoor air. A cracked heat exchanger is a serious issue as it can reduce heating efficiency and, more importantly, allow carbon monoxide to leak into your home, which is extremely dangerous. Recognizing the warning signs early can prevent a health hazard and costly furnace damage. North Country Aire will share how to tell if your furnace may have a cracked heat exchanger.

Yellow or Irregular Flame

A properly functioning furnace produces a steady blue flame in the burner. If you notice a yellow, flickering, or irregular flame, it could indicate incomplete combustion due to a crack in the heat exchanger. The crack can allow air to mix with the combustion gases, disrupting proper ignition and creating a yellow flame. Turn off the furnace immediately and schedule a professional inspection. Never attempt to operate a furnace suspected of having a cracked heat exchanger.

Soot or Rust Inside the Furnace

Cracks in the heat exchanger can cause soot buildup or rusting inside the furnace cabinet. This occurs as combustion gases escape and deposit particles where they shouldn’t be. If you think your furnace has a cracked heat exchanger look for black soot on burners or around the furnace and rusted metal components near the heat exchanger. Have a licensed HVAC technician examine your furnace. Soot and rust are indicators of poor combustion and potential structural damage to the heat exchanger.

Strange Furnace Noises

If you hear popping, cracking, or banging sounds coming from your furnace, it could indicate a heat exchanger problem. These noises often occur as the metal expands and contracts around a crack or weak spot. Other possible noises to watch for are rattling or clanging or continuous vibration during startup. Shut down your furnace and call a professional. Ignoring these sounds can worsen the crack and increase the risk of dangerous gas leaks.

Increase in Carbon Monoxide Levels

A cracked heat exchanger can allow carbon monoxide (CO) to leak into your home. This odorless, colorless gas is extremely dangerous and can be fatal in high concentrations. Warning signs of CO exposure include headaches or dizziness when home heating is on, nausea or fatigue or other flu-like symptoms without an actual illness. Install a carbon monoxide detector near your furnace and bedrooms. If it goes off, evacuate immediately and call emergency services. Schedule a furnace inspection right away.

Frequent Furnace Repairs

If your furnace is running constantly but not producing enough heat, or if you’re calling for frequent repairs, a cracked heat exchanger could be the underlying cause. A crack can reduce heating efficiency by allowing hot gases to escape instead of heating the air circulated through your home. Schedule a professional inspection to determine whether repairs are possible or if a furnace replacement is necessary.

Age of Your Furnace

Older furnaces, usually 15 years or more, are more prone to developing heat exchanger cracks due to repeated thermal stress. If your furnace is nearing or past this age, regular inspections are especially important to detect early signs of cracks.

Boiler & Furnace Heating Inspection, Troubleshooting, Diagnosis, Repair, Tune Up Maintenance & More in Mora, Cambridge, St. Francis, Oak Grove, North Branch & Greater Isanti, Minnesota

A cracked heat exchanger is a serious issue that affects both safety and comfort. Regular furnace maintenance and annual inspections are the best ways to catch heat exchanger issues early, keeping your home warm and safe all winter long. North Country Aire can ensure a safe and reliable heating system. Call us today.