Dangers of a Cracked Heat Exchanger

Gas Furnace Heat Exchanger

In a properly functioning gas furnace system, the flue transfers carbon monoxide and other gases produced by combustion safely out of the house. A damaged or blocked flue can result in those gases going into the home instead. A gas furnace’s heat exchanger is another potential source of leaked carbon monoxide. The heat exchanger contains the gas combustion chamber. As air is circulated through the HVAC system, it passes over the heat exchanger and absorbs thermal energy before it’s circulated throughout the house. Over time, the heat exchanger can crack or separate, allowing carbon monoxide to enter the house.

The Causes of Cracks in Heat Exchangers

Heat exchangers are subjected to extreme temperatures, and as they heat up and cool down over the course of a heating cycle, their metal expands and contracts; this stress alone makes them susceptible to cracking. However, there are additional factors that can worsen the chance of cracking.  Conditions that lead to excessive heating will accelerate the deterioration of the heat exchanger.  One condition is too little airflow through the system which is often the result of an oversized furnace combined with comparatively undersized ductwork.

Contrastingly, too much airflow, reduces the furnace’s normal operational temperatures, can be equally damaging. A furnace’s vent gas needs to be kept at certain temperatures to prevent the moisture in the gas from condensing in the wrong place within the system.  The moister that is generated when gas is burnt is slightly acidic with can corrode a heat exchanger over time.

How an AirPlus Trained Professional Identifies a Cracked Heat Exchanger

Initially, a cracked heat exchanger is a problem that will go unnoticed by most homeowners. However, professional HVAC technicians always check heat exchangers for damage during their pre-season maintenance inspection. The first step is pesimply to look where most homeowners can’t.  In addition to visual inspections an AirPlus technician will use other methods check the integrity of the heat exchanger as well such as checking the burner flame for disturbance.

Dangers of a Cracked Heat Exchanger

If a crack has been detected in the heat exchanger it is advised to have it replaced as soon as possible as the crack will only get worse; the more severe the crack the more dangerous the situation.  Also, the older, natural or atmospheric draft furnaces can leak larger quantities of gas because the inside of the heat exchanger is under slightly higher pressure than the air coming  into the house.

One of the easiest things a home owner can do is install a carbon monoxide detector and check regularly that it is working.

Enlisting Certified, Trained Professional Help

Homeowners with a newer-model furnace may have a more favorable outcome in the event that a crack develops in their heat exchanger. In newer furnaces, most heat exchangers have a longer warranty than most other parts—often 10 years, 25 years or lifetime exchange.   However, the warranty on a heat exchanger rarely includes labor costs.  The process of replacing a heat exchanger is a very labor-intensive because the furnace has to be completely disassembled and then reassembled.

Most homeowners with older furnaces find it more cost-effective to upgrade to a more efficient furnace that provides additional benefits including lower operating costs.

Regular Furnace Maintenance is Crucial to Continued Safety and Efficiency

Homeowners have some influence over how fast their heat exchanger wears out. Maintenance is the key. During yearly checks, a trained and certified technician can resolve potential contributors to cracked heat exchangers with a few important tasks, included in an AirPlus Precision Performance Safety Inspection & Cleaning.

Each year, gas furnaces are becoming safer and more efficient, however regular maintenance is crucial to continued safety and efficiency.  With many residential HVAC issues, preventative care is every homeowner’s wisest strategy.  The more you keep your furnace clean and running efficiently, the better the performance you’ll receive, the more reliable it will be and the longer it will last.

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