Cracked Heat Exchanger Diagnosis For Your Furnace in Indianapolis

By: Brian Schutt  |  November 15, 2023

Updated: Fall of 2023

Chances are if you’re reading this, you’ve had a technician out to your home for a furnace repair and you’ve been told there’s a crack heat exchanger in your furnace. First off, you need to know what heat exchangers do in your furnace. As we discuss in the video below, this is the enclosed metal area where in a gas furnace flames shoot into, where the heat is actually created for your home.

As gas furnaces age, they can develop these types of crack heat exchanger issues that can cause serious health consequences from carbon monoxide leaked into your home.

The issue that we see in Indianapolis HVAC, is that many companies use this very real threat as a means to force customers into buying new furnaces, when it may not really be necessary.

First thing to know: whenever you get a cracked heat exchanger diagnosis, the technician should be able to show you the crack.


If they say it’s not a visible crack, but they have a CO detection device that found a crack, ask them to show you. It’s not that you’re questioning their credibility, you’re just wanted to see for yourself. The Homesense technicians get trained on this process during Heat Exchanger Expert Certification classes.

Another trick to be aware of is technicians using an inspection scope tool with a camera to “show” customers the crack. While this is sometimes the only way to show a crack that isn’t directly visible, the trick to be aware of is that sometimes this will be a recording taken of another furnace. Ensure you are watching a live inspection being done during this process.

Either way, you should get a second opinion from another company before moving forward.

Let’s say you do have a cracked heat exchanger, this is what your next steps would look like:  The reality is that most heat exchangers have a 20 year to lifetime warranty anymore.  However, even with the part under warranty, labor costs can be very high, because many furnaces have to be disassembled and reassembled, as the heat exchanger is a major part.  Since we don’t usually see a cracked heat exchanger until the furnace gets older, and many people don’t see the benefit of replacing a $2,000+ part on an old system, we end up recommending replacing the entire furnace.

Once you talk about replacing the furnace, you have plenty of options.  And, unless the crack heat exchanger is very prominent, don’t feel pressured to make an immediate decision, though we encourage you to do so within 24 hours of the initial diagnosis and to have a CO detector in the home to ensure you’re not at any major risk. We are required by code to shut down any furnace that has a cracked heat exchanger because of the carbon monoxide risk.

Call Homesense for a second opinion on a cracked heat exchanger diagnostic, and get an honest assessment from one of our award winning technicians.

Posted in: Heating

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