How much does it cost to replace a furnace heat exchanger?

Author: Catalina Monahan  |  Last update: Sunday, June 7, 2026

Unfortunately, the cost of replacing a heat exchanger isn't the most affordable choice. The cost of replacing a heat exchanger ranges from $2,000 to $3,500. Replacing your furnace's heat exchanger would be a good route to take if your furnace is fairly new.

Is it worth replacing a heat exchanger?

So, if your furnace is still under its labor warranty, we definitely recommend replacing just the heat exchanger since most of the repair cost will be covered under warranty. But if your furnace is no longer under the labor warranty and it's over 10 years old, you might as well just replace the furnace completely.

What is the life expectancy of a furnace heat exchanger?

In the past, heat exchangers were often built with heavy metals, such as cast iron. These exchangers can last as long as 30 or 40 years, much longer than the steel exchangers most manufacturers build today. Modern stainless or aluminized steel heat exchangers typically have a life span of 15 to 25 years.

Can you replace just the heat exchanger in a furnace?

Replacing just the heat exchanger and not replacing the entire furnace is an option. If your furnace is less than ten years old and the rest of the components are in good condition, it will likely be worth just replacing the heat exchanger component.

How do I know if my furnace heat exchanger is bad?

However, there are some common signs that can indicate potential damage. These include observing cracks or corrosion on the heat exchanger, detecting unusual smells or odors when the furnace is running, such as a strong metallic or burning scent, and experiencing frequent furnace shutdowns or malfunctions.

How Much Does A Furnace Cost?

Will a furnace still run with a cracked heat exchanger?

Although a furnace will continue to heat your home even with a cracked heat exchanger, it is not safe to continue using your furnace. Using a cracked heat exchanger allows for certain toxic gases to escape from the furnace including carbon monoxide, nitrous oxide, and sulfur dioxide.

How many hours does it take to replace a heat exchanger?

Because replacing a heat exchanger can take up to eight hours or longer, it represents the bulk of the cost. If your warranty is expired, and you would need to pay both parts and labor for a new heat exchanger, look further into whether a full unit replacement would be more advantageous for you.

How much is labor to replace a 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 to estimate the cost of a heat exchanger?

The popular method is to use the cost per area of the heat exchangers which is determined using an overall heat transfer coefficient U from A =Q/UΔT m but the challenge with this method is that obtaining the heat exchanger areas can be complex.

How often do heat exchangers fail?

While heat exchangers are typically manufactured to last between 10 – 20 years, many factors can accelerate the process of heat exchanger failure. These factors usually fall under the categories of poor maintenance, poor initial system design and installation, or poor equipment design by the manufacturer.

Should I replace a 20 year old furnace?

Furnaces 20 years old or older become increasingly inefficient over time and can crack and leak, putting you and your family in danger. If your furnace is between 16 and 20 years old and constantly breaking down, then you should strongly consider having it replaced.

What are the symptoms of a faulty heat exchanger?

What are the symptoms of a damaged heat exchanger?
  • Yellow or distorted flames. When the boiler is on, the burner flame should be steady and blue in colour. ...
  • Leaking water. A crack can cause the heat exchanger to leak water. ...
  • Carbon monoxide alarm is sounding. ...
  • Odd smells. ...
  • Banging or whistling noises.

How many heat exchangers are in a furnace?

Primary Heat Exchanger

Furnaces that are 70-80% efficient have one heat exchanger. The more efficient a heat exchanger is, the less energy needs to be spent heating your home. Some furnaces only have a single heat exchanger, but more efficient ones often also have a secondary heat exchanger.

Does a cracked heat exchanger make noise?

However, a high-pitched rattling before your furnace kicks on might indicate a cracked heat exchanger, a more serious problem that may require replacement.

What is the cost of a new furnace?

How much does a new furnace cost? New furnace cost can vary significantly. Gas furnaces costs can range from as little as $3,800 for a basic unit with installation to more than $10,000 to $12,000 for a high-efficiency model with professional installation.

What is the most reliable gas furnace brand?

The 5 Best Furnace Brands
  • Carrier Furnace: Best Warranty.
  • Lennox Furnace: Best Company Reputation.
  • Bryant Furnace: Best for Durability.
  • Trane Furnace: Most Years of Experience.
  • Amana Furnace: Best for Efficiency.

Can you replace your own heat exchanger?

And remember, trying to replace a heat exchanger without professional assistance can pose potential hazards such as carbon monoxide poisoning and other safety risks.

Why are heat exchangers so expensive?

However, if your heat exchanger goes bad (more on that in the next section), the cost of labor is what makes heat exchangers so expensive to replace.

How do you check a heat exchanger?

By using a combustion analyzer. This tool measures the efficiency of fuel burning appliances by determining the temperature and CO and oxygen levels. If the combustion analyzer detects low appliance efficiency, it means there's a combustion problem. A furnace combustion problem is a sign of a cracked heat exchanger.

What causes a heat exchanger to go bad?

Clogged filters reduce the air flow that result in development of cracks inside the system. Other reasons for reduced air flow are the dirty fan blades, dirty duct work, and obstructed air vents. All of these factors can cause major damage to the heat exchanger.

How much does a heat exchanger unit cost?

Typically, new heat exchangers can range anywhere between £400 - £600, so it often makes more sense to buy a brand-new boiler, especially if your current one is an older inefficient one with an expired warranty.

How long should a furnace last?

What is the average life of a residential furnace? A furnace that receives regular maintenance can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend the life of a furnace even longer.

Is it expensive to replace a heat exchanger in a furnace?

Unfortunately, the cost of replacing a heat exchanger isn't the most affordable choice. The cost of replacing a heat exchanger ranges from $2,000 to $3,500. Replacing your furnace's heat exchanger would be a good route to take if your furnace is fairly new.

How do I know if my heat exchanger is broken?

Because the heat exchanger is made out of metal, as it is heated cracks will expand/contract, and can cause rattling, popping, and/or banging noises. Presence of Carbon Monoxide. Carbon monoxide (CO) is an odorless, colorless, and tasteless flammable gas which is toxic.

Previous article
Why is my bathroom turning blue?
Next article
Why does my AC unit run when my furnace is on?