We're proud to offer multiple financing options!

Learn More

HVAC 101: Cracked Heat Exchanger

Cracked heat exchanger

Gas furnaces are extremely common in Georgia and Alabama homes. This equipment is made up of many components that facilitates the heating process, with the heat exchanger being one of the most critical. With proper maintenance, they are fairly safe. However, when furnaces are neglected, a cracked heat exchanger may exist under your nose, putting your entire household in danger’s path.

In this blog, the technicians at Energy Savers discuss what a heat exchanger is and why a cracked heat exchanger is a serious issue. Energy Savers helps you protect your furnace and your family with heating system maintenance, inspections, and repairs.

What Is a Heat Exchanger?

A heat exchanger is a device that transfers heat from one medium to another. They’re used in all sorts of applications where heat is collected or generated and moved to a second use or component. Engines and refrigerators use them, as well as HVAC systems.

The heat exchanger inside your furnace plays an important role in home comfort. It is the component that heats the air cycling through the HVAC system. Composed of a set of tubes or coils looped repeatedly, the air flows through the furnace and comes into contact with the heat exchanger. Contact with the heat exchanger’s hot surface transfers heat to the air before moving throughout the ductwork in your home. The type of fuel and furnace model dictate the shape of the coils.

How Does a Heat Exchanger Work?

A gas furnace uses gas fuel to generate heat. The thermostat initiates a heating cycle when temperatures in the home drop below a set temperature. When the signal is received by the furnace, the gas valve opens, and the burners are ignited by the ignition system to burn the fuel inside the furnace’s combustion chamber. 

The heat exchanger is connected to the combustion chamber. Combustion gases travel inside the heat exchanger, raising the temperature of its metal surfaces. Air circulates over and is warmed by this heat. 

Byproducts of combustion stay safely concealed inside a properly functioning heat exchanger so they do not mix with the home’s air supply. What happens to these gases after they serve their purpose depends on the type of furnace:

  • The heat exchanger is connected to the flue pipe to vent combustion gases outside the home in standard-efficiency furnaces.
  • Some high-efficiency furnaces feature a secondary heat exchanger to increase heat extraction from the combustion process. Gases move from the primary to the secondary heat exchanger, allowing further use of combustion energy to heat the home. By removing such a substantial amount of heat from the gases, they convert to a liquid form in the secondary heat exchanger and drain out of the system through a drain line.

How Does a Cracked Heat Exchanger Occur?

Over time, heat exchangers can crack. As the metal of this component is constantly exposed to extreme heat then cooled, the metal expands and contracts. After so long, weak points develop and cracks can form. A cracked heat exchanger is inevitable due to wear and tear of this crucial component. A heat exchanger can be replaced or the entire furnace may be upgraded when this issue appears.

Sometimes, a heat exchanger crack can form early in the furnace’s service life. The issue is typically caused by overuse or lack of maintenance. If your air filter is clogged, the furnace has to strain to push air through the system. This issue results in poor airflow through the furnace – proper airflow is needed to prevent overheating of components. This strain can lead to early cracks. Likewise, if there is excessive wear and tear on your furnace, due to short cycling, improperly sized equipment, or other stressors, a crack can develop early.

Why Is a Cracked Heat Exchanger a Serious Concern?

A cracked heat exchanger presents a major safety risk. First, a crack creates a path that allows gases from the combustion process to escape. Normally, gases are vented safely out of the home. When a heat exchanger cracks, combustion gases escape and mix with the air that circulates into the home. One such gas is carbon monoxide (CO). Exposure to carbon monoxide can be deadly.

According to the Centers for Disease Control and Prevention, at least 430 people die each year in the U.S. from accidental, non-fire-related CO poisoning. 

Because carbon monoxide is odorless and colorless, humans cannot detect its presence without the help of specialized equipment. It is important to have carbon monoxide detectors properly installed throughout the home if a gas furnace is used. Carbon monoxide poisoning can cause headaches, nausea and loss of consciousness. 

A cracked heat exchanger can also start a furnace fire. When gas and air fail to correctly mix in the furnace, non-combusted gas can build up in the heat exchanger. Once the temperature is high enough, the gas can become explosive. If a heat exchanger is cracked, flames are forced out through the cracks and may spread.

How to Prevent Cracks in Your Heat Exchanger

The simplest method to prevent a heat exchanger from cracking is to follow a regular maintenance schedule. Professional HVAC technicians use specific methods to inspect the heat exchanger for cracks.

During a regular service visit or tune up, technicians perform comprehensive inspections. As part of the inspection, techs visually examine the heat exchanger for damage and signs of potential cracks, including rust or corrosion. The burner flame is also observed. Cracked heat exchangers allow air into the combustion chamber, which causes a visual disturbance to the flame.

In addition to regular maintenance, check your air filter monthly. A clogged air filter strains your system. Most homeowners find it needs to be replaced every two to three months. If you have a smoker or multiple pets in your household, monthly changes are probably more appropriate.

Finally, install carbon monoxide detectors in addition to smoke detectors. Install one unit on every level of the home and outside of any sleeping areas at minimum. Read the manufacturer’s instructions to determine if the unit should be mounted on the ceiling or on a wall. Consider a linked system that triggers all alarms throughout the home when one unit detects the presence of carbon monoxide. Carbon monoxide poisoning can lead to serious health issues and even death.

For Heat Exchanger Help in Georgia and Alabama, Call Energy Savers

Energy Savers has helped home and business owners achieve the best heating efficiency and comfort for more than 40 years. We also service and repair all brands of HVAC equipment and provide air quality solutions.

If you would like to schedule a tune up or repair for your furnace, please call us, or submit the form online. We also service heat pumps and ductless heating units. We are happy to help you keep your heating system in service so you stay comfortable and warm all winter long. If you find you are ready to upgrade to a more modern, energy-efficient system, we can help there, too.

Energy Savers provides quality products and great customer service in and around Columbus, Georgia and Opelika, Alabama. For healthy air and better comfort in communities such as Fort Benning or Waverly Hall, Georgia, call us for help today.

Skip to content