Close-up of cracked heat exchanger

What’s a Cracked heat exchanger and why should I care?

With the holidays approaching, spending time with your loved ones in the comfort of your home is more important than ever. So, this month we want to talk about the dangers of having a cracked heat exchanger and what you can do to have peace of mind this holiday season.

How does it work?

If you’re like most homeowners, you may be asking yourself what a heat exchanger is and what does it do?

A heat exchanger is a series of tubes located between the combustion chamber and the blower inside your gas furnace. The heat exchanger’s purpose is to heat the air passing over it. At the same time, it isolates the air within your home from the combustion process.

Imagine blowing on a fresh, hot cup of coffee in the morning in order to cool it down. The warm air you generate by blowing on your coffee is the same process being used to heat your home. As air within your furnace is passed over the heat exchanger, it picks up heat from the heat exchanger’s surface. It is then distributed throughout your home.

Causes of a cracked heat exchanger

Heat exchangers are often subject to extreme shifts in temperature and repeated, frequent use during the heating season. This means that, like any other vital component, they may eventually fail (crack). The most common cause of a cracked heat exchanger is simply time and use. If your furnace is more than 10 years old, the cracks may just be a sign of wear and tear. The metal surface of the heat exchanger is subjected to years of temperature extremes combined with expansion and contraction from multiple heating seasons.

Another potential cause of cracking is limited air flow. Blocked registers, dirty filters, and ductwork obstructions can cause pressure to build up in the furnace. This pressure will only increase the strain on the metal surface of the heat exchanger. It may eventually cause it to fail prematurely.

Finally, if your furnace is too large for your home you may be asking for a cracked heat exchanger. Improperly sized equipment always runs the risk of putting a strain on your HVAC system. Oversized furnaces often cycle on and off more frequently. This can further expose your exchanger to excessive expansion and contraction as the internal temperature fluctuates back and forth multiple times per day.

Signs of a cracked heat exchanger

  1. A change in flame color– a typical furnace flame should be steady blue. If the flame has a yellow tint to it, this could mean the gas mixture is contaminated due to a crack in your heat exchanger. 
  2. There’s a buildup of soot inside the heat exchanger– if you notice a large amount of soot inside your heat exchanger, this is a sign that the furnace is failing to burn the gas entirely.
  3. You smell a strong odor in your home– a faulty heat exchanger can emit a formaldehyde-like odor. This is a strong indicator that there is a crack in your system.

If you have any reason to suspect a cracked heat exchanger, call a professional immediately!

What can go wrong with a cracked heat exchanger?

Having a crack in your heat exchanger is not only harmful to your system, but the resulting gas emissions have the potential to cause property damage, illness or even, in extreme situations, death. When cracks form in the metal surface of your exchanger, your furnace becomes more at risk for health hazards. We’re talking fire and the leakage of harmful gases into your home.

First off, the buildup of combustible gases from a leaky heat exchanger has the potential to result in the flames escaping the combustion area and even spreading to other nearby materials. Gas furnaces require gas and air in specific quantities to produce heat. When that balance is thrown off, the system may produce flames which can escape the confines of the furnace. The flames seek out oxygen and other flammable materials in the immediate area.

Another potential hazard is the risk of a carbon monoxide leak. Inhaling this hazardous gas can lead to many health issues, such as, headaches and flu-like symptoms. Routine HVAC system maintenance combined with a carbon monoxide detector is typically the best way to ensure your protection from carbon monoxide being leaked into your home.

Contact us!

Having a crack in your heat exchanger should not be taken lightly, which is why we recommend routine maintenance for your furnace by a qualified professional. If you suspect there is a crack in your system, do not try to fix it yourself! Call an AC Masters service technician or schedule an appointment to have your furnace inspected. As a family owned and operated business, we know how important a safe environment is for you and your loved ones. 

With the holiday season in full swing, we know that your time is valuable. That is why, when you schedule an appointment with us, we promise our HVAC professionals will provide you with the same level of quality, care, and peace of mind we expect for our own families. Give us a call today with all of your HVAC questions and service needs at 757-898-2894

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