If you use a gas furnace to heat your home, the heat exchanger is an important component for your heating operation. The furnace heat exchanger is responsible for taking heat from the combustion process and transferring it to the air circulating around your home. When combustion gases enter the exchanger, the metal components are heated up. As the furnace blows air over the hot exchanger, the air air is heated and then pushed throughout your home. The heat exchanger is completely sealed and attached to the furnace flue, ensuring that combustion gases are safely vented outside your home.
Under normal circumstances, your furnace operation is completely safe and provides an efficient heating source for your home. However, throughout normal wear and tear, the metal heat exchanger expands and contracts as part of the heating process. As a result, it’s common for heat exchangers to develop stress cracks. If this happens, combustion gases can escape into your home and create potential fire and safety hazards. Let’s take a closer look at detecting problems with a cracked heat exchanger.
To keep your furnace running smoothly and safely, it is important to inspect your unit routinely. An annual inspection of your furnace will turn up many issues such as small leaks, worn belts, or loose connections. A thorough inspection should also include a check of the heat exchanger. If there are problems, you will probably be able to see visible cracks or holes in the heat exchanger. How well you can see the heat exchanger will be dependent on the make and model of your furnace. If your routine check does uncover cracks, holes, or other issues, you’ll want to have those addressed as soon as possible. Cracks can appear anywhere on the heat exchanger components and can be in the form of large gapped openings or small cracks or openings. It is important to do a thorough inspection regularly as even small cracks can allow dangerous gases to escape and create a safety issue.
During normal operation, your furnace has a visible steady blue flame that burns inside of the unit. This flame is an essential part of the heating process. However, if you notice an abnormal flame, it could be a symptom of an issue. Instead of a blue one, a yellow flame could highlight a problem with a cracked or damaged heat exchanger. The exchanger can no longer properly transfer heat from the furnace to the air when this happens. Additionally, you will notice that your furnace cannot heat your home as efficiently. These signs likely indicate improper combustion. If you notice a yellow flame or a diminished or flickering flame, you should call an HVAC professional to evaluate the heat exchanger and offer solutions for the problem.
One of the more noticeable signs of a cracked heat exchanger is the presence of a strong chemical smell. The odor is often thought to resemble the smell of formaldehyde. The chemical odor released from a cracked exchanger is toxic. Long-term exposure to a cracked exchanger odor can lead to headaches, nausea, and other symptoms. You’ll want to take precautions and stay a safe distance from the heat exchanger if you smell anything strange. Additionally, you should call a professional technician to solve the problem as soon as possible.
Your furnace is a very efficient and safe appliance that provides comfortable temperatures to your home all winter long. While your gas furnace is normally very safe, occasionally, some issues could develop that might pose an issue. A cracked heat exchanger can create a very dangerous situation and could allow harmful carbon monoxide into your home. A carbon monoxide leak could trigger several health problems. It is important to have your gas furnace regularly inspected by a qualified HVAC technician to prevent any issues. Additionally, you should pay close attention to any signs that indicate a problem with your furnace or heat exchanger.