How Much Does it Cost to Replace a Furnace Heat Exchanger in San Marcos?

Have you just been told by a tech that you need a new furnace heat exchanger?

If so, you’ve probably also heard that heat exchangers are very expensive to replace (so expensive that it might be better to get a new furnace).

It’s true: Heat exchangers are pricey. Here in San Marcos, the cost to replace a furnace heat exchanger ranges from $1,500 to $3,500+.

In this article, we’ll cover the following topics:

What is a heat exchanger and why is it so expensive to replace?
Why do heat exchangers need to be replaced?
Should I replace my furnace entirely or just the heat exchanger?

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What is a heat exchanger and why is it so expensive to replace?

The heat exchanger (pictured below) is a series of coils inside your furnace that heat your home’s air.

Furnace Blower — *The inside of a furnace.*

Here’s how the heating process works: The burners in your furnace heat the coils of the heat exchanger. Once cold air blows over the heat exchanger, these hot coils transfer their heat to the air which ultimately warms up your home.

Since heat exchangers are literally the part of your furnace system that heats your home, most manufacturers usually offer 20-year or lifetime warranties on the part itself.

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.

You see, it can take up to 10 hours for a tech to replace a bad heat exchanger because they’ll need to disassemble the furnace to remove the old heat exchanger and install a new one.

Now that you know what a heat exchanger is and why it’s so expensive to replace, let’s look at what makes a heat exchanger go bad in the first place...

Why do heat exchangers need to be replaced?

Heat exchangers need to be replaced if their metal coils are visibly cracked.

A cracked heat exchanger is a potential safety hazard for your family because it means gases from the combustion process are mixing in with the air you breathe.

This is problematic because those gaseous fumes include carbon monoxide, which can cause severe illness or death if humans breathe it for an extended time.

What causes a heat exchanger to crack?

The most common cause of a cracked heat exchanger is overheating.

Overheating can be caused by a number of issues, including:

Lack of regular furnace maintenance
A dirty furnace filter
Worn out pressure valves
An oversized furnace

All of these overheating problems cause the heat exchanger’s coils to expand and contract, which can eventually lead to stress cracks in the coils around weak areas like bends and welds.

How to know your heat exchanger needs to be replaced

If a tech comes to your home and says you need to replace your heat exchanger, ask them to physically point out the crack.

According to the Air-Conditioning, Heating and Refrigeration Institute (AHRI), “Any crack or hole that is big enough to affect combustion will be easily visible to the naked eye.”

That means the tech should point out to you exactly where the crack is so you can see the heat exchanger needs to be replaced.

Unfortunately, some dishonest techs use deceiving methods like smoke testing to “prove” you have a cracked heat exchanger. However, these methods are not accurate, and are often used to scare homeowners into buying a new furnace when they don’t really need one.

Bottom line: Beware of any tech who insists you have a cracked heat exchanger but can’t show you the crack. If you can’t see it, you don’t have a crack.

Should I replace my furnace entirely or just the heat exchanger?

Let’s say you can see the cracks in your heat exchanger and you know you need a new one. Now you’ll have to determine if it’s better to pay for a new heat exchanger or a new furnace altogether.

Here’s our recommendation: If your furnace is around 15 years old, it’s probably better to replace your furnace instead of paying for a new heat exchanger. You see, furnaces typically only last 15 to 20 years, which means your furnace will need to be replaced soon anyways. Better to replace your furnace sooner rather than waste additional money repairing an old furnace.

On the other hand, if your furnace is young and has been maintained regularly, then replacing the heat exchanger may be the most cost effective option.

Have more heat exchanger questions? We have answers.

Whether you’re ready for a new heat exchanger, or you just want a second opinion about your current heat exchanger, our techs can help.