← All articles

How Much Does it Cost to Replace a Heat Exchanger in Denver?

December 21, 2016

Uh-oh. Your furnace repair person just said you have a cracked heat exchanger. 

The first question on your mind is, “How much does it cost to fix it?”

Well, the average cost to replace a heat exchanger in Denver ranges from $2,000 to $3,500.

Pretty pricey, huh?

That’s because heat exchangers are one of the most expensive and labor-intensive components of a furnace to replace. 

There are other factors that can affect the price of this repair too. These include:

  • Your furnace heat exchanger warranty: You could save about $500 to $600 if your warranty is still valid.
  • The type of heat exchanger: More efficient furnaces have more expensive heat exchangers.
  • The HVAC consultant you call: Every company charges differently. Some charge a flat rate; others, by the hour. It takes about 5 to 8 hours to replace a heat exchanger, which adds to the high cost.

In this article, we’ll go into more detail to help you understand:

  • How heat exchangers work
  • If yours actually needs replacing

Let’s start with the basic question:

What’s a heat exchanger?

A furnace heat exchanger is a thin-walled metal device designed to remove the heat from burned gas and transfer that heat into your home’s air.

Here’s how: Your furnace’s blower sucks in cold air from your home and blows it over over the heat exchanger, heating the air. The blower then delivers that heated air into your home.

How to know if your furnace exchanger needs replacing

Some HVAC techs try to scare you into replacing the heat exchanger when you really don’t need to. So, for your information, you know you’ll need a new heat exchanger if it’s cracked or not.


Some technicians try to show you cracks in the heat exchanger by using water or a smoking agent, but those tests won’t accurately indicate the problem is with your heat exchanger. Why? Because a heat exchanger isn’t sealed airtight. Water can leak out of a heat exchanger even if it does not have a dangerous crack! 

So be wary of any technician who uses only those methods to determine your heat exchanger’s health. 

So, what should they do?

According to the Air-Conditioning, Heating and Refrigeration Institute (AHRI), your HVAC technician should visually inspect all heat exchanger surfaces. If it’s cracked, they should be able to show you.

“Any crack or hole that is big enough to affect combustion will be easily visible to the naked eye,” according to the AHRI guidelines for furnace heat exchanger inspections.

He or she may also look at soot build up or the burner flame color to infer that you could have a broken heat exchanger.

Why a cracked heat exchanger must be replaced

The AHRI guidelines continue: “If there are any abnormal splits, cracks, or holes, the heat exchanger must be replaced.”

Why is that so?

A cracked heat exchanger can allow deadly carbon monoxide to contaminate your household air. Unfortunately, some HVAC companies use carbon monoxide poisoning as a scare tactic to persuade people to buy a new furnace unnecessarily. Keep in mind all the tips we mentioned above so you’re not to tricked into replacing the heat exchanger when you don’t need to! 

Replace the heat exchanger or install a new furnace?

Let’s assume your heat exchanger is actually cracked. Because heat exchanger repairs are so expensive, should you replace it or get a new furnace?

Well, it depends on the age of your furnace. The average lifespan of a furnace is 12-15 years. If your furnace is close to that age, you may consider just buying a new furnace. With an older furnace, there are other parts that will break and need replacing soon, anyways. The cost of repairing each part could add up to the price of a new furnace.

On the other hand, if your furnace is fairly new, in good condition and you still have a valid warranty, then replacing the heat exchanger may be the most cost effective option.

Still have heat exchanger questions?

Whether you just want a second opinion or just want some advice about your furnace heat exchanger, we’re here to help. If you live in Denver, contact Plumbline Services for a free furnace install estimate.

Related articles