Everything You Should Know About Heat Exchanger Failure

Make sure to get annual maintenance on your HVAC systems to uphold your warranties.

Everything You Should Know About Heat Exchanger Failure

Everything You Should Know About Heat Exchanger Failure

9 December 2019
, Blog

There's plenty that can go wrong with your furnace. However, one of the more serious problems you could encounter involves your heat exchanger. That's the part of your furnace that takes the valuable heat generated by burning fossil fuels and safely transfers that heat into your home. A heat exchanger failure can easily sideline your furnace and condemn your home to chilly temperatures.

What Causes Heat Exchanger Failure?

The vast majority of heat exchanger failures can be traced back to overheating. Stress cracks can form throughout the heat exchanger if it overheats, especially near bends, welds, and joints. Blocked airflow due to damaged vents or a clogged air filter can set the stage for overheating and eventually expose the heat exchanger to stress cracks.

Rust and corrosion can also eat away at the heat exchanger, thus causing damage that ranges from pinhole leaks to moderate cracks and holes. Condensate made acidic by combustion byproducts can contribute to corrosion.

How Bad Can It Be?

A crack or hole in the heat exchanger not only makes your furnace lose some of its heating capacity, but it can also pose a silent but deadly danger to your home. Stress cracks can allow hazardous gases, including carbon monoxide, to escape from the heat exchanger while your furnace runs. A steady buildup of the odorless and colorless gas can cause headaches, dizziness, disorientation, and fatal injuries.

How Will You Know When It Happens?

That's the problem with heat exchanger failure; it's hard to tell when it happens. Fortunately, there are a few signs you can look out for:

  • Heavy soot buildup in and around the furnace
  • Strange odors similar to formaldehyde
  • Stress cracks in other, more visible furnace components
  • Yellow or flickering burner flames
  • Symptoms of carbon monoxide poisoning

Seeing or experiencing any of the above should warrant a call to your HVAC specialist immediately for furnace repair. Upon arrival, your technician will examine your heat exchanger in-depth for signs of cracks or corrosion.

What Can You Do About it?

If you think a simple repair is in order, think again. There's no safe way to repair a cracked or rusted-out heat exchanger. On top of that, reaching the heat exchanger is an ordeal of its own; accessing the problem often means dismantling most of your furnace. At this point, a complete furnace replacement becomes the cheaper and less time-consuming option. A brand-new furnace is the best option for dealing with a heat exchanger failure, especially if your current furnace is over 15 years old.  

About Me
It's More Important Than You Think

I used to routinely get calls from HVAC contractors in my area offering annual maintenance contracts. As soon they would identify themselves, I would quickly say no thank you and hang up. After all, my heating and cooling system was working fine. Why would I spend money on services I clearly didn't need? Boy was I wrong! A few years ago, my AC unit suddenly stopped working. I called my HVAC contractor to have it repaired and assumed that my warranty would pick up the bill. That was until I learned my warranty was voided due to a lack of maintenance. Out of nowhere, my decision to ignore those maintenance calls was about to cost me more than a $1,000. I know there are others out there like me. It is my hope that this site will provide them with the knowledge they need to avoid the mistakes I made.