Cracked Heat Exchanger: What It Means and What You can Do Next

September 20, 2022

A furnace is almost always a background player for your home, helping keep you warm during the cold winter months. It regularly isn't noticed until something breaks down.

One source may be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to know the symptoms of a cracked heat exchanger and what to do if you are worried that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger transfers heat from the combustion chamber in your furnace to the air that moves inside the ventilation. It typically accomplishes this with coils or tubes that warm the air while functioning as a barrier to keep gas produced in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its important role, it’s no surprise that a cracked heat exchanger can pose a risk. A damaged heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to flow through your home.

For this reason, do NOT run your heater if you think it has a cracked heat exchanger, as letting it run could make the whole family sick. Contact an HVAC professional right away if you are worried your furnace has a cracked heat exchanger that should be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace shuts off: A crack in your heat exchanger may cause your furnace to switch off.
  • Odd Smells: If the air leaving your furnace has a strong chemical scent, it could be an indicator that gas is slipping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you notice poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm may go off or household members may struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unusually tired, get out of the home right away and then call for help.
  • Soot: If you spot black sooty accumulating near the exterior of your furnace, it’s an indication something may be seriously wrong.

What to Do if a Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, hire a pro with extensive experience in furnace installation Heflin as soon as possible so they can take a look at your system and, if necessary, 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 review the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it could significantly shrink your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the best ways to avoid problems in your furnace overall is through consistent furnace maintenance. Furnaces offer the most benefits when they work efficiently. Hiring a certified professional to inspect your furnace for old parts, dirty filters and other common problems can keep you from getting a big bill later on.

It’s also a good idea to inspect your furnace filters every few months – it’s encouraged 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 your entire furnace work more vigorously to do its job. And the harder your furnace works, the more wear and tear components like the heat exchanger will endure.