The heat exchanger plays a critically-important role in the safe operation of your furnace. Essentially, this metal component keeps the combustion fumes produced by the furnace’s fuel burner contained so they’re safely directed up the system’s exhaust flue. If the device fails for any reason, those fumes containing toxic gases including carbon monoxide can escape into the warm air being distributed through your home. Here are some common heat exchanger-related issues that can occur.
Rusting Out From Condensation
Condensation that causes corrosion and rusting-out of the heat exchangers can be a concern if you have a high-efficiency furnace. These models, with an AFUE rating of 90 percent or higher, produce condensation that’s sent out through a condensate drain line, as with an air conditioner. If the drain is partially blocked, condensation can back up into the furnace and gradually deteriorate the heat exchangers inside. Eventually, holes can form and allow hazardous gases to escape. In a standard-efficiency furnace, condensation doesn’t usually form, unless the exhaust pipe is undersized.
Development of Hairline Cracks
Heat exchangers endure repeated heating and cooling cycles during the normal operation of a furnace. Over time, this can cause metal fatigue, and cracks start to develop in the material. This is one of the main reasons why furnaces eventually need replacement, but it can also occur prematurely from:
· Inadequate airflow through the system due to closed registers or a clogged air filter. This causes repeated overheating and premature metal failure.
· Improper combustion at the burner, which can also lead to overheating or flame impingement and early metal fatigue.
How to Avoid Heat Exchanger-Related Problems
Having your furnace serviced annually by a knowledgeable HVAC professional is the best way to avoid heat exchanger-related issues. A trained technician will clean the furnace, make needed adjustments to the burner, ensure proper system airflow and check for cracks/corrosion on the heat exchanger so your heating system stays running reliably and safely.
If you’re concerned about the condition of the heat exchanger in your furnace, contact us at Arpi’s Industries, proudly serving the HVAC needs of Calgary-area homeowners for over 50 years.
Our goal is to help educate our customers in Calgary, Alberta about energy and home comfort issues (specific to HVAC systems). For more information about home heating systems and other HVAC topics, download our free Home Comfort Guide.