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

September 20, 2022

A furnace is often a background player in your home, helping keep you warm in the cold winter months. It frequently won't be noticed until a malfunction appears.

One cause may be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to learn the signs of a cracked heat exchanger and what you can do if you believe that is 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 moves through the ventilation. It typically accomplishes this using coils or tubes that heat the air while functioning as a barrier to keep gas formed in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its central role, it’s no surprise that a broken heat exchanger can be hazardous. A damaged heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to flow across your home.

For obvious reasons, never use your furnace if you suspect it has a cracked heat exchanger, as this could make the whole household ill. Contact an HVAC professional immediately if you think your heating has a cracked heat exchanger that should be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: A crack in your heat exchanger could cause your furnace to switch off.
  • Strange Smells: If the air escaping your furnace has a powerful chemical smell, it could be a sign gasses are slipping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you feel symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm should go off or household members may experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel unusually tired, leave the home as soon as you can and then call for help.
  • Soot: If you notice black sooty accumulating around the exterior of your furnace, it’s more evidence something might be seriously wrong.

What to Do if the Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, call a pro experienced in furnace installation Brookfield as soon as possible so they can examine your system and, if needed, start a furnace heat exchanger replacement. Costs will differ depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are often protected by the warranty. It's a good idea to confirm the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it can significantly shrink 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 via routine furnace maintenance. Furnaces offer the most benefits when they work efficiently. Calling a certified professional to examine your furnace for old parts, clogged filters and other potential problems can keep you from getting a big bill later on.

It’s also beneficial to review your furnace filters every few months – it’s ideal 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 harder to accomplish its job. And the harder your furnace has to work, the more deterioration pieces like the heat exchanger will experience.