Regardless of the Brand of equipment, having cracks in your heat exchanger is not an uncommon occurrence. Over time, the natural expansion and contraction of the metal heat exchanger during each heating and cooling cycle can lead to metal fatigue and cracks, especially in older furnaces. These cracks can also be caused by poor airflow from a clogged filter or blocked ducts, an oversized furnace that “short cycles,” or corrosion. Cracked heat exchangers can be a serious safety hazard because they can leak deadly carbon monoxide into your home. With that said, understand the facts to make an informed and educated decision before repairing or replacing your furnace. Ask for proof by looking at the live camera view/pictures of the crack. Also ask to see the CO reading the technician is taking.

Area Heating & Cooling’s technicians are trained to do safety inspections on your equipment. One of the ways we do this is to use a camera to inspect the equipment’s overall health. We are looking for signs of rust, corrosion and any cracks in the heat exchanger. We also perform a carbon monoxide level reading. It is rare that carbon monoxide levels are found to be at a dangerous level, even with visible cracks. However, we are unable to predict when and if the crack will expand further or if the carbon monoxide levels will rise.

What causes cracks and how to prevent them?

Normal wear and tear: Over time, the natural expansion and contraction of the metal heat exchanger during each heating and cooling cycle can lead to metal fatigue and cracks, especially in older furnaces.

Insufficient airflow: A dirty or clogged air filter, blocked ducts, or obstructed registers can restrict airflow, causing the furnace to overheat and the heat exchanger to crack prematurely.

Improper furnace sizing: A furnace that is too large for your home can “short cycle,” turning on and off frequently. This puts excessive stress on the heat exchanger from rapid, repeated heating and cooling.

Corrosion: Acidic byproducts from combustion can corrode the heat exchanger over time, leading to cracks. 

Prevention

Perform regular maintenance: Schedule annual professional inspection and service for your furnace. Use a trusted HVAC company.

Change the air filter: Replace your furnace’s air filter twice a year or as needed.

Ensure proper sizing: When installing a new furnace, make sure it is sized correctly for your home. This can be verified by a heat load performed by a certified consultant at a trusted HVAC company.

Check Your Carbon Monoxide Detectors: Make sure your detectors are working and showing a reading of zero. If they’ve gone off, go outside and call for help right away.

What is an unhealthy level of CO2?

Learn more at https://www.cdc.gov/carbon-monoxide/about/

Learn more at http://epa.gov