Headaches, Soot, or CO Alarms Going Off? A Cracked Heat Exchanger Could Be the Hidden Danger in Your Furnace.
A cracked heat exchanger is likely the last thing most homeowners think about when a furnace develops issues. However, a cracked heat exchanger is one of the most significant and potentially dangerous furnace problems. Strange furnace noises, soot around the furnace base, or carbon monoxide (CO) alarms going off are symptoms that may have a hidden crack in the heat exchanger, causing the issue.
SE Michigan winters can be harsh. A reliable furnace is essential to comfort and safety when the temperature is freezing. Luckily, by knowing the dangers of a cracked heat exchanger and when to call in your local trusted HVAC company, you can help keep your home and family safe.
In this blog, we will cover:
• Common signs of a cracked heat exchanger
• Why they form
• How they affect furnace performance and safety
• What to do to prevent potentially costly repairs and dangerous outcomes
What is a Heat Exchanger?
The heat exchanger is the furnace part that extracts heat from the combustion process to warm up the air that circulates through your home. Fuel combustion happens inside the heat exchanger. It contains the hot combustion gases that are separated from the air that flows through your home via the ductwork. This separation is vital because it ensures that combustion byproducts such as CO don’t enter your home’s living space. Instead, the gases go to the exhaust flue when the furnace is on.
If the heat exchanger cracks, that separation is broken. Even a small crack can allow CO and soot into the air your family is breathing. Many early warning signs of a cracked heat exchanger are subtle. That is why most homeowners do not realize something is wrong until the symptoms become more severe.
Common Signs of a Cracked Heat Exchanger
If you experience any of these symptoms, you may have a cracked heat exchanger and a significant safety issue in your home:
Unusual Furnace Sounds
Popping, cracking, or banging when the furnace turns on or is running can indicate that there are stress fractures in the heat exchanger.
Visible Soot Around the Furnace
Black soot around the furnace cabinet or on the floor near the unit is a sign that combustion byproducts are leaking into your home.
Frequent Furnace Cycling or Inability to Heat
Short cycling or difficulty providing comfortable air throughout your home could mean a stressed heat exchanger.
Illness or Flu-Like Symptoms
Headaches, dizziness, nausea, and persistent fatigue when the furnace is operating could be a sign of carbon monoxide exposure.
Carbon Monoxide Alarm Activation
CO alarms are designed to alert you to potentially dangerous gas concentrations in your home. If one goes off when the furnace is running, do not ignore it. This is one of the most important signs that something is wrong with your furnace. Get it serviced as soon as possible.
Increased Utility Bills
A decreased efficiency or a cracked heat exchanger can reduce furnace performance. When that happens, the system has to work harder and drive up energy costs.
Why Heat Exchangers Crack
Heat exchangers are made to tolerate extreme temperature fluctuations as the furnace turns on and off throughout the day. However, eventually, that constant expansion and contraction can create stress points in the system, particularly in older furnaces or systems that experience irregular furnace maintenance. Other common causes include:
• Manufacturing defects
• Lack of routine furnace maintenance and repair
• Overheating from clogged filters or restricted airflow
• Corrosion over time, especially in coastal areas or high humidity
Homeowners throughout Iceberg Heat and Air’s service area in cities and towns like Belleville, Milan, New Boston, and Taylor report seasonal furnace issues more commonly during peak winter months. This is why regular furnace maintenance visits are so important. These visits will help identify small issues that can be fixed before they lead to cracked heat exchangers.
Why a Cracked Heat Exchanger is Dangerous
Efficiency issues are not the only issue with a cracked heat exchanger. A cracked heat exchanger is a critical safety issue. The biggest safety risk is carbon monoxide (CO) exposure. CO is an odorless, colorless gas that can accumulate in your home without your knowledge. Flu-like symptoms and general exhaustion are easy to overlook in the early stages. Symptoms will get worse as the situation gets more serious.
Children, elderly family members, and pets are particularly at risk of CO exposure. CO alarms are designed to detect potentially dangerous gas concentrations. If one goes off when the furnace is running, turn off the furnace. Contact a professional service technician immediately.
In extreme cases, a cracked heat exchanger can also lead to a fire hazard or even a complete furnace failure, which will leave you without heat on the coldest nights.
What to Do if You Suspect a Cracked Heat Exchanger
If you notice soot, weird noises, or frequent CO alarm triggers, turn off your furnace and contact a licensed HVAC professional immediately. Do not try to diagnose or fix a serious furnace issue yourself. A certified technician has the tools and training to inspect your heat exchanger to see if repairs or a replacement are necessary.
Iceberg Heat and Air offers comprehensive furnace diagnostics throughout SE Michigan and the surrounding areas, including:
• Ann Arbor
• Canton
• Flat Rock
• Monroe
• Romulus
• Saline
• Westland
Our certified technicians use specialized equipment to test for cracks, check for CO leaks, and ensure your heating system is operating safely and efficiently.
How Iceberg Heat and Air Keeps Your Family Safe
For furnace safety and care, local trust matters. Iceberg Heat and Air has been serving SE Michigan homes and businesses with dependable heating and cooling services for decades. We focus on safety, comfort, and peace of mind for all our customers.
Our services related to cracked heat exchangers include:
• Professional furnace inspections and heat exchanger assessments
• Carbon monoxide testing and alarm integration support
• Routine furnace maintenance plans to prevent major failures
• Reliable furnace repair and replacement services
• Emergency response services if a safety risk is detected
Homeowners in Dundee, Erie, Allen Park, and Rockwood regularly post positive feedback about their experiences with Iceberg technicians. You can check out real customer reviews and testimonials on the Iceberg Heat and Air reviews page to see how others in your community trust us for HVAC service.
We also proudly serve all local neighborhoods and communities listed on our service area page. This means families throughout SE Michigan have access to fast, professional heating and cooling service.
How to Prevent a Cracked Heat Exchanger
Routine maintenance is one of the best ways to prolong the life of your furnace and avoid dangerous outcomes like a cracked heat exchanger. The following tips are vital to consider:
• Schedule an annual furnace tune-up before heating season begins.
• Change furnace air filters regularly for good airflow.
• Keep vents and returns clean and free from obstructions.
• Listen for unusual furnace sounds and call for service early.
• Install and test CO alarms on every level of your home.
Taking a proactive approach to furnace care can help catch minor issues before they become major problems. Your trusted SE Michigan HVAC company can develop a customized maintenance plan to best suit your home’s needs and the age of your system.
Iceberg is Ready to Fix Your Cracked Heat Exchanger
A cracked heat exchanger is no small issue. From headaches and soot to CO alarms going off, a cracked heat exchanger can present itself in both alarming and subtle ways. Since your heat exchanger is such a critical component for safety and performance, it is important to detect and address issues early with professional service.
If you suspect a cracked heat exchanger is in your furnace, contact Iceberg Heat and Air for an inspection and reliable solution. Iceberg Heat and Air technicians are trained to identify and address heat exchanger issues with the utmost care and expertise. Serving all of SE Michigan, Iceberg Heat and Air is your trusted partner in home comfort and safety.
Cracked Heat Exchanger FAQ
What causes a heat exchanger to crack?
Heat exchangers can crack from regular heating and cooling cycles, corrosion, manufacturing defects, lack of maintenance, restricted airflow, and overheating.
Can a cracked heat exchanger be repaired or does it need to be replaced?
In most cases, a cracked heat exchanger cannot be repaired and must be replaced to ensure safe and correct operation of the furnace.
How soon should I act if my carbon monoxide alarm goes off when the furnace is running?
Switch off the furnace immediately and contact a licensed HVAC service company. Do not ignore CO alarms; they are there to protect you from potentially dangerous gas exposure.
Are there early warnings before a heat exchanger cracks completely?
Yes. Strange furnace sounds, soot buildup, unexpected short cycling, rising energy bills, or flu-like symptoms when the heat is on are all signs of trouble.
Does regular maintenance help prevent heat exchanger issues?
Yes. Annual furnace tune-ups and regular filter changes help keep good airflow and avoid placing too much stress on the heat exchanger.
