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

September 20, 2022

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

One cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to know 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 of your furnace to the air that circulates throughout the system. It usually handles this with coils or tubes that heat up the air while acting as a barrier to keep gas formed in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its important role, it’s no surprise that a damaged heat exchanger can be hazardous. Cracks in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to circulate across your home.

For this reason, never use your heating if you think you're dealing with a cracked heat exchanger, as this could make the whole family ill. Contact an HVAC professional immediately if you think your heater has a cracked heat exchanger that should be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace switches off: A crack in your heat exchanger can cause your furnace to switch off.
  • Odd Smells: If the air coming out of your furnace has an intense chemical scent, it may be evidence gas is slipping through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm initiates or you feel symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm could go off or household members might start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel sick, exit the home right away and then call for help.
  • Soot: If you spot black sooty collecting on the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, call a pro well versed in furnace installation Greater Richmond right away so they can take a look at your system and, if required, handle a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

However, the good news is that heat exchangers are often included in the warranty. You should check the warranty paperwork on your furnace, as while the warranty won't always cover the entire cost of repairs, it still may significantly reduce your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to avoid problems in your furnace overall is with consistent furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Calling a skilled professional to examine your furnace for old 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 changed 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 longer to do its job. And the harder your furnace needs to run, the more strain components like the heat exchanger will endure.