While replacing a furnace heat exchanger can be a significant expense, it’s an essential investment in your safety. What is the cost to replace HVAC heat exchanger? It can range between $1,000-$4,000 for parts and labor, with an average cost of $2,000. Learn how this heat exchanger cost breaks down and how to identify the crucial signs it’s cracked and needs replacement.
How Much Does a Heat Exchanger Cost?
The actual heat exchanger component can cost $300-$3,000, depending on the size and brand of your furnace. Fortunately, the heat exchanger is one of the most reliable furnace components, making multiple replacements extremely rare. Most also come with a 10-20 year warranty that covers its cost.
How Much Does Labor Cost to Replace a Heat Exchanger?
Generally, labor to replace a heat exchanger costs $400-$600. The job can take 5-8 hours at a cost of $75-$125 per technician. Furnaces operate the same way regardless of if they use natural gas, propane or oil. Consequently, the type of furnace you have doesn’t affect the cost.
What is a Heat Exchanger?
Now that you know the cost of a replacement, it’s helpful to know what is a heat exchanger and how it operates. The heat exchanger is a furnace component that plays an essential role in heating your home. It consists of looping tubes and coils inside an enclosed metal chamber that heat the flowing air. Once the walls of the heat exchanger are adequately heated, it sends this heat out to your home through ducts.

The heat exchanger is inside a metal chamber to contain the combustion gases the furnace generates as it heats the air inside. These gases can include nitrous oxide, sulphur dioxide and carbon monoxide, which can be dangerous to inhale. The heat exchanger is vented to release these gases outside. However, a cracked heat exchanger can release them into your home, jeopardizing your safety.
How Can I Tell if My Heat Exchanger is Cracked?
A cracked heat exchanger is one of the most common reasons for a replacement. It’s important to test for cracks because replacement can save you the higher expense of replacing the entire furnace. To test the heat exchanger, a technician may use a combustion analyzer to provide oxygen and carbon monoxide readings. If the analyzer calculates a high reading, the heat exchanger may need to be replaced.
These are also common signs of a cracked heat exchanger:
Furnace Flame Looks Yellow
A functioning gas furnace displays a steady, blue flame. A flame that flickers and appears yellow could mean that either the burner is dirty or the heat exchanger is cracked. If the flame flickers more when the fan is on, it’s likely due to a cracked heat exchanger.
Furnace Components Corrode and Form Cracks
Stress cracks in exterior components occur as the furnace expands and contracts during heating and cooling. The cracks will often corrode when they’re exposed to fumes or moisture. Unfortunately, corroded exterior cracks are a good indicator that interior cracks are also present.
Water Collects on the Floor Around the Furnace
Water around the floor of the furnace can also indicate issues with an attached humidifier or a clog in the HVAC drain system. However, these issues usually exhibit condensation on other furnace components. If there is no visible condensation and water has collected on the floor around the furnace, the heat exchanger may be cracked.
Furnace Produces a lot of Soot
Soot on the internal side of the furnace indicates incomplete combustion. While this could be due to a burner that needs adjusting, a cracked heat exchanger can also result in an excess of soot.
The System Produces a Strong Smell
A cracked heat exchanger can produce a strong smell of formaldehyde. This smell often causes headaches or other physical ailments. If you detect a strong smell from the furnace, contact a professional service immediately.
The experts at Dependable Heating and Air can replace a furnace heat exchanger and perform the regular maintenance that keeps your system safe. Call us for all your HVAC system needs.