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

September 20, 2022

A furnace is usually a background player at home, ensuring you're warm across the cold winter months. It frequently doesn’t get noticed until a malfunction appears.

One cause may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s worthwhile to know the signs of a cracked heat exchanger and what you can do if you are worried that is the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger transfers heat from the combustion chamber of your furnace to the air that circulates through the ventilation. It typically handles this via coils or tubes that heat the air while acting as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its key role, it isn't surprising that a broken heat exchanger can be very dangerous. A crack in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed through your home.

For that reason, never use your heater if you suspect there's a crack in the heat exchanger, as letting it run could make the whole household sick. Call an HVAC professional right away if you are worried your heating has a cracked heat exchanger that should be repaired.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace turns off: Cracks in the heat exchanger may cause your furnace to shut off.
  • Unusual Smells: If the air coming out of your furnace has a powerful chemical scent, it may be an indicator that gasses are leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm is triggered or you feel poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm should go off or family members may struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel unwell, get out of the home immediately and then call for help.
  • Soot: If you find black sooty buildup near the exterior of your furnace, it’s more evidence something may be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, contact a professional well versed in furnace installation Montoursville right away so they can examine your system and, if needed, handle a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates often hover around $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are generally included in the warranty. You’ll want to review the warranty paperwork on your furnace, because while the warranty won't always cover the entire cost of repairs, it can significantly reduce your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the most convenient ways to avoid problems in your furnace overall is with consistent furnace maintenance. Furnaces work the best when they run efficiently. Calling a skilled professional to examine your furnace for worn-out parts, clogged filters and other likely problems can keep you from getting a big bill later on.

It’s also beneficial 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 drawing air through a clogged filter makes your entire furnace work harder to accomplish its job. And the harder your furnace works, the more strain components like the heat exchanger will experience.