There’s never a good time to find out that your home’s furnace has a cracked heat exchanger. The heat exchanger is the component that contains the high-temperature furnace burner flame while transferring generated heat into the system airflow. An intact heat exchanger seals toxic combustion gasses—including dangerous carbon monoxide—out of the airflow and diverts them safely up the vent flue to the outdoors.
What’s The Danger?
A crack in the heat exchanger can allow carbon monoxide and other toxic combustion byproducts to leak into the system airflow and spread poisonous fumes throughout your house.
Though not every crack in a heat exchanger leaks carbon monoxide when first discovered, the cracking process advances steadily. A small crack that doesn’t yet leak almost always expands into a larger crack that eventually does.
Why Did It Happen?
The number one cause of a cracked heat exchanger is simply age. Constant expansion and contraction of the metal as the unit heats and cools over the years results in cracking. Other causes include:
- Low system airflow that overheats the heat exchanger.
- Internal rust due to condensation forming inside the exchanger.
- Incomplete combustion causing the burner flame to be too hot.
What Now?
The American Gas Association recommends that a heat exchanger with a crack of any size must be replaced for safety reasons. In many locales, an HVAC technician or utility company employee who discovers a cracked heat exchanger is legally required to shut down the furnace and shut off the gas supply to the unit—a procedure called “red tagging”—so it cannot be restarted until the heat exchanger is replaced or a new furnace is installed.
The heat exchanger is typically the most expensive single component in a furnace. Often, the price of the component plus labor may approach the cost of a new furnace. Therefore, if your unit is older than 10 years, purchasing a new furnace—with higher efficiency and updated technology—is usually the preferable option versus replacing the heat exchanger alone.
For advice about the critical issue of a cracked heat exchanger, contact the heating professionals at Energy 1 Heating & Air Conditioning.
Energy 1 Heating & Air Conditioning
1 (440) 246-5440
Serving the Lorain, OH Area