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

September 20, 2022

A furnace is usually a background player in your home, helping keep you warm in the cold winter months. It often doesn’t get noticed until a malfunction appears.

One root cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to familiarize yourself with the signs of a cracked heat exchanger and what you should do if you suspect that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps transition heat from the combustion chamber inside your furnace to the air that circulates throughout the ventilation. It typically accomplishes this via coils or tubes that heat the air while acting as a barrier to keep byproducts created in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its key role, it’s no surprise that a broken heat exchanger can be hazardous. Cracks in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to flow through your home.

For this reason, do NOT turn on your heater if you believe you're dealing with a cracked heat exchanger, as this could make the whole family sick. Call an HVAC professional as soon as possible if you believe your furnace has a cracked heat exchanger that needs repair.

Four Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: A cracked heat exchanger may cause your furnace to turn off.
  • Odd Smells: If the air leaving your furnace has a powerful chemical scent, it could be evidence gasses are slipping through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm goes off or you notice symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm may go off or household members might struggle with signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel sick, leave the home as soon as you can and then call for help.
  • Soot: If you find black sooty accumulating near the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, hire a pro experienced in furnace installation Branchville right away so they can inspect your system and, if required, start a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are generally included in the warranty. You should review the warranty paperwork on your furnace, as while the warranty may not cover the entire cost of repairs, it can significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the most convenient ways to prevent a problem in your furnace overall is via regular furnace maintenance. Furnaces offer the most benefits when they run efficiently. Contacting a skilled professional to inspect your furnace for worn-out parts, dirty 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 aren't connected to the heat exchanger itself, the strain of drawing air through a clogged filter makes the entire furnace work more vigorously to do its job. And the harder your furnace works, the more deterioration parts like the heat exchanger will experience.