Warning signs of a cracked heat exchanger

A cracked heat exchanger in a gas furnace can be dangerous to you and your family and should never be ignored. If your heat exchanger is cracked or broken, deadly carbon monoxide can be released into your home, causing a serious health hazard.

It’s nearly impossible to determine if a heat exchanger is cracked by visual inspection alone, but the signs we’ve listed below can give you an idea of whether you should call a professional HVAC technician to inspect your furnace’s heat exchanger:

• Check the flame: A normally operating gas furnace will have a steady blue flame. A burner with a moving yellow flame could be a sign of a dirty burner or a cracked heat exchanger.
• Cracks and Corrosion: When your furnace’s external components show signs of wear, the internal components could be damaged as well. Stress cracks can develop due to expansion and contraction that occurs each time the furnace heats and cools. Additionally, internal components can become corroded because of exposure to fumes that emit chloride or exposure to moisture from other sources.
• Soot: Black carbon buildup (aka soot) inside the furnace is a result of incomplete/inefficient combustion. This can be a sign of either poorly adjusted burners or a cracked heat exchanger.
• What’s that smell? A compromised heat exchanger produces a strong and unpleasant odor similar to formaldehyde. This can cause severe headaches and other physical symptoms. If you smell this unusual odor, you should call a qualified HVAC technician as soon as possible.
• Physical symptoms: Gases emanating from a cracked heat exchanger can cause frequent headaches as well as flu-like symptoms. Pollutants, such as carbon monoxide, nitrogen dioxide and sulfur dioxide, can cause eye and nose irritation, disorientation, sleepiness and nausea. If you experience these symptoms only when you are home and the heat is on, there’s a high probability that your heat exchanger is cracked. Call an HVAC technician who has the ability to test air quality, as well as fix your heat exchanger.

Safety first and foremost

Always make sure your home has a working carbon monoxide detector near your furnace. This will help tip you off to any potential heat furnace issues. And always make sure you have a full maintenance inspection done at least once a year. A little bit of prevention can go a long way in keeping your family safe.