Cracked Heat Exchanger: What It Means and What to Do Next

September 20, 2022

A furnace is often a background player at home, ensuring you're warm during the cold winter months. It frequently won't be noticed until something goes wrong.

One source might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to familiarize yourself with the evidence of a cracked heat exchanger and what you can do if you are worried that might be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps move heat from the combustion chamber of your furnace to the air that flows throughout the system. It generally handles this with coils or tubes that heat up the air while serving as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its central role, it shouldn't come as a surprise that a broken heat exchanger can be very dangerous. Cracks in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to flow through your home.

For that reason, never use your heating if you believe it has a cracked heat exchanger, as this could make the entire household ill. Call an HVAC professional as soon as possible if you think your furnace has a cracked heat exchanger that needs repair.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A cracked heat exchanger could cause your furnace to shut off.
  • Odd Smells: If the air coming out of your furnace has an intense chemical scent, it could be an indicator that gas is leaking through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm initiates or you feel symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm should go off or family members may experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unusually tired, exit the home as soon as you can and then call for help.
  • Soot: If you find black sooty buildup on the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, contact a pro with extensive experience in furnace installation Elk River as soon as possible so they can take a look at your system and, if needed, perform a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are regularly included in the warranty. It's a good idea to check the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it could significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the easiest ways to avoid problems in your furnace overall is with regular furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Contacting a trained professional to inspect your furnace for old parts, clogs in the air filters and other potential problems can keep you from getting a big bill later on.

It’s also helpful to take a look at your furnace filters every few months – it’s recommended some filters be replaced every 90 days or sooner if they are dirty or grimy. While the filters are not part of the heat exchanger itself, the strain of dragging air through a clogged filter makes the entire furnace work more vigorously to accomplish its job. And the harder your furnace has to work, the more wear and tear parts like the heat exchanger will endure.