If your home is like most throughout the Roswell area and beyond, then you use a furnace for your heating needs. Given that gas is so widely available, it’s very likely this heating system is gas-powered. A gas furnace produces a large amount of heat, and it does so at less expense than using an electric furnace, since natural gas costs less than electricity per unit.
However, there’s a potential hazard with using a gas furnace. We aren’t saying that to scare you—gas furnaces are not inherently dangerous, after all—especially with all the safety features built into today’s models. But older furnaces or furnaces that haven’t been well cared for over the years have one specific danger that needs to be watched for—a cracked heat exchanger.
What’s a Heat Exchanger?
This is essentially what enables a furnace to heat up the air that travels through the ventilation system. When the burners of the furnace come up, they generate hot combustion gas, which is collected inside the heat exchanger—a metal chamber or series of chambers. For more insights, check out what you should know about your gas furnace heat exchanger to understand its critical role in heating and safety.
The hot combustion gas in the heat exchanger heats up the metal walls, and the blower fan of your furnace comes on and sends air around the exchanger, where it picks up the heat from the furnace wall and continues into the ductwork. In this way, the combustion gas heats the air without the gas ever needing to come in contact with it.
Once this heating process is finished, the combustion byproducts in the heat exchanger are vented out of the system through a flue, to release the gas harmlessly into the air.
When a Heat Exchanger Is Damaged
Since the metal of a heat exchanger expands and contracts as it heats and cools, and also since furnaces can accumulate a lot of wear and tear over the years from natural causes, the strain eventually can cause a crack to form on the heat exchanger. Corrosion, due to the reaction between the combustion gas and the metal, can also weaken the metal to the point that it cracks. This is often due to improper venting, which is one of the many problems that is checked for during furnace maintenance.
Regular maintenance is crucial to catch early signs of these issues. During a professional inspection, technicians can assess whether buildup, poor airflow, or blocked exhaust vents are increasing the likelihood of corrosion. Addressing these concerns early not only prevents cracks but also helps your furnace operate more efficiently, lowering energy costs over time.
The cracks might be very small, but since the exchanger expands with the heat, the cracks open enough to allow some of the combustion gasses to escape and enter your airflow. The gas you should be concerned with is carbon monoxide—it is tasteless and odorless, and in severe cases even deadly. If you’ve noticed any unusual heater behavior, such as odd sounds, refer to heater noises you don’t want haunting you to identify potential warning signs.
Beyond carbon monoxide, leaking combustion gases can also include nitrogen dioxide and sulfur dioxide, which may irritate respiratory systems even in small quantities. Prolonged exposure to these gases, especially in homes with inadequate ventilation, can exacerbate symptoms for individuals with asthma or other respiratory conditions. This further highlights the importance of addressing any damage to your heat exchanger promptly.
Another critical concern with a damaged heat exchanger is the potential for reduced furnace efficiency. Cracks disrupt the heat transfer process, meaning your system has to work harder to provide the same level of warmth. Over time, this can lead to higher energy bills and unnecessary strain on other furnace components, increasing the likelihood of system breakdowns.
Aside from carbon monoxide, escaping combustion gases can also introduce moisture into your system, leading to rust and further corrosion. This can create a cycle of damage that not only impacts the heat exchanger but can also compromise other critical components of your furnace, making timely repairs even more essential.
How to Tell If You Have a Cracked Heat Exchanger
First, we can’t stress enough how important it is to have a carbon monoxide (CO) detector in your home. So that if a cracked heat exchanger does allow this harmful gas in, you’ll be alerted to it right away. CO occurs naturally in our environment, but when it’s leaking into your sealed up home, it becomes a health and safety hazard.
Another important precaution is scheduling annual furnace inspections and tune-ups. These proactive measures allow HVAC professionals to detect early signs of wear and tear, such as hairline cracks or improper ventilation, before they escalate into significant safety or efficiency concerns.
While a CO detector is your first line of defense, visual cues can also point to a cracked heat exchanger. Rust or soot buildup near the furnace, or a yellow burner flame instead of a steady blue one, may indicate incomplete combustion or a leak. These signs should prompt an immediate call to a professional to avoid potential hazards.
Aside from ensuring the proper precautions are in place, you should also listen for a clicking soon after the blower shuts off. This is a sign of a CO leak and cracked heat exchanger. Even if you only suspect there may be a problem, it’s always best to call in a pro to investigate. If your furnace has been running for years, learn how long you can expect your furnace to last to assess whether repair or replacement is the better option.
Other signs to watch for include unusual smells, such as a strong or sharp odor near your furnace, which could indicate escaping combustion gases. Additionally, if you notice uneven heating throughout your home or rising energy bills without a clear explanation, these could also point to a compromised heat exchanger. Acting quickly when you spot these warning signs can prevent more serious issues down the line.
In addition to listening for unusual noises, keep an eye out for physical symptoms among household members, such as headaches, dizziness, or fatigue. These could indicate low-level carbon monoxide exposure from a compromised heat exchanger. If multiple people experience these symptoms at the same time, evacuate the home immediately and contact emergency services before seeking professional furnace repair.
When you need quality furnace repair in Roswell, GA, contact DC Cheek Heating, Cooling & Plumbing—Fixed, at the Speed of Life!
