Symptoms of Cracked Heat Exchanger on Your Furnace

One of the most common furnace issues Indiana homeowners face is a cracked heat exchanger. Fortunately, your furnace will likely show signs to indicate you’re dealing with this problem so you can take action. The team at Dugan Air Heating and Cooling is highly skilled at performing all types of furnace repairs, including addressing cracked heat exchangers and more.

Common Symptoms of a Cracked Heat Exchanger

Here are some common signs and symptoms that may indicate a possible crack in your heat exchanger.

Unusual smells

A chemical or dusty smell or a burnt odor could mean you have a cracked furnace heat exchanger. If you’ve recently replaced your air filter and still notice these odors, your furnace needs immediate professional attention to address a possible carbon monoxide leak. In most cases, homeowners notice these odors as soon as they turn the furnace on. 

If you notice an unusual smell or a burning odor coming from your furnace, turn it off immediately and turn off the gas supply going to the furnace. Open your doors and windows to ventilate your home. Contact your local gas company to notify them of the odors, then call Dugan Air for a professional inspection and repair. 

Soot buildup around the furnace

Visible soot buildup around your furnace may mean the heat exchanger is cracked. Soot appears when the cracked component disrupts the combustion process and causes it to burn fuel incompletely. Combustion gases can escape before the heat is fully transferred, leading to soot formation. Look for a fine, black, powdery substance around your furnace if you suspect this is the issue. 

The furnace flame turns yellow instead of blue

The pilot light in your furnace should always have a steady, blue flame. A flickering or yellow (or orange) flame is one of the most common cracked heat exchanger symptoms. When the heat exchanger is cracked, air mixes with fuel and causes improper burning. Never ignore a yellow pilot flame — call Dugan Air right away.

Strange or loud furnace noises

Some furnace noises are normal, but new or unusually loud sounds may indicate an issue with your heat exchanger or another component. Common noises associated with a cracked heat exchanger in your furnace include popping, whistling, banging, or scraping sounds from the furnace cabinet. These noises may occur when the metal expands and contracts due to temperature changes or if the crack is large enough to cause a sudden change in pressure. 

Visible cracks on the heat exchanger

A visible crack is the most obvious sign of an issue with your heat exchanger. Examine the component closely for any cracks or splits. Visible cracks are commonly accompanied by strong chemical or gas-like odors, whistling sounds, or a flickering, yellow pilot light flame. Water leaking from your furnace may also be a sign of a cracked heat exchanger.

What To Do if You Suspect a Cracked Heat Exchanger

A cracked heat exchanger poses a serious safety risk due to the potential of a dangerous carbon monoxide (CO) leak. This odorless, colorless gas can cause a range of serious health issues and can even cause death. A cracked heat exchanger can also reduce the efficiency of your furnace, raise energy costs, and lead to uneven heating or a complete malfunction of the system. 

If you notice any of the above signs or suspect a cracked heat exchanger, follow these steps: 

• Step one: If possible, turn off your furnace and the gas supply going to your home, then open the doors and windows to increase ventilation.
• Step two: Leave your home and call your local gas company immediately if you suspect a gas leak.
• Step three: Contact an experienced HVAC company for an emergency furnace inspection.
• Step four: If the HVAC technician confirms you have a cracked heat exchanger, discuss whether you need a repair or replacement.
• Step five: Install carbon monoxide detectors throughout your home to alert you of a possible gas leak. 
• Step six: Enroll in a regular preventative maintenance plan to help your furnace operate safely and optimally for years to come. 

Contact Dugan Air for Premium Service

Knowing the signs of a cracked heat exchanger keeps you safe and preserves the functionality of your furnace. If left ignored, a cracked heat exchanger poses a threat to your furnace and your health.

The NATE-certified technicians at Dugan Air provide top-notch furnace inspections, repairs, and replacements with a touch of Irish charm. Contact us to schedule an appointment and experience the Dugan Difference today!

Frequently Asked Questions

What causes a heat exchanger to crack?

Overheating due to dirty air filters or ductwork, worn control valves, and prolonged wear and tear due to expansion and contraction are the most common causes of a cracked heat exchanger.

Can a cracked heat exchanger be repaired?

In some cases, a cracked heat exchanger can be repaired by welding the cracks. However, older furnaces may need to have the heat exchanger or the entire unit replaced if the damage is too extensive. 

How can I prevent a cracked heat exchanger?

The best way to prevent a cracked heat exchanger is to schedule regular furnace maintenance, including professional inspections and tune-ups. Visually check your furnace to look for damage, and keep air filters and ductwork clean and free of obstructions to encourage proper airflow and prevent overheating.