Your furnace relies on a heat exchanger to warm air before it circulates into your home. Unfortunately, like other components of your home heating system, heat exchangers experience malfunctions, which spell trouble for your home. Read on to learn more about what heat exchangers do, why they crack, and how a cracked heat exchanger threatens your health. 

What Do Heat Exchangers Do?  

Furnaces contain heat exchangers, which are designed to receive heat created by combustion and transfer it to the air. As the heating process occurs, combustion heats the metal of your heat exchanger. When air passes over the heat exchanger, it absorbs the warmth. Warmed air moves into your home with the help of the blower. High-efficiency furnaces sometimes contain two heat exchangers, which uses combustion waste to add more heat, resulting in a higher amount of usable heat from the energy consumed. 

What Causes Cracked Heat Exchangers? 

Unfortunately, heat exchangers are able to crack, which allows byproducts from combustion to enter your breathable air. Here are a few things that cause a cracked heat exchanger. 

Dirt and Grime

Over time, the interior components of your furnace become laden with dust and dirt, which clogs blowers and covers coils. When this occurs, air is incapable of passing through the area to be warmed, and the burners may continue to heat without being able to warm the air efficiently. As a result, the system overheats, which has the potential to cause a cracked heat exchanger. 

Improper Filter Changes

Air filter replacement is essential to allow proper airflow through the furnace. A dirty air filter severely restricts airflow so the furnace is unable to regulate its temperature. When the furnace overheats, heat exchanger cracks are able to develop. 

Oversized Unit

When furnaces are too big for the home they are designed to heat, moisture builds up inside the furnace. Natural gas produces a small amount of water during the combustion process. In a properly sized furnace, this condensation burns off after about 10 minutes of run time. However, if furnaces are too large, they reach the set temperature prior to that time so they shut off and the system stays wet and rusts. 

This short cycling also forces the metal of the heat exchanger to expand and contract frequently, which stresses the component and leads to cracks. To avoid a cracked heat exchanger and other furnace problems, your home heating load needs to be calculated carefully. 

Why Are Cracked Heat Exchangers Dangerous? 

Unfortunately, since carbon monoxide is also a natural byproduct of combustion, it has the potential to leak out of a cracked heat exchanger. Carbon monoxide is a colorless, odorless gas that causes flu-like symptoms such as fatigue, confusion, dizziness, and nausea. Carbon monoxide exposure also causes death, which is why cracked heat exchangers are such a serious problem. 

However, the cracks need to be fairly large to cause a significant CO leak. This makes the problem easier for a skilled HVAC technician to identify during a furnace inspection. When your inspection is performed before cold weather and using your heating system begins, a cracked heat exchanger is found and fixed before it poses a risk to your family.

We Offer Free Estimates

The best way to detect a potentially hazardous cracked heat exchanger is to schedule a furnace tune up or inspection. Here at Hans Heating & Air, we focus on impeccable same-day service that our clients can count on. From free estimates on new equipment to three-year guarantees on repairs, rest assured that your furnace will be fixed the right way the first time.