Purpose of the Heat Exchanger:

The heat exchanger inside of the furnace serves two purposes.  First, when the blower motor starts, it allows the cold air from the returns to go around the heat exchanger and out of the supply vents.  As the heat exchanger warms from the burners flames, the warm air is distributed through the supply vents.  Second, the heat exchanger keeps the exhaust gasses from being mixed in with your homes breathable air. 

Every heat exchanger should have an air tight seal separating the gases inside and the breathable air around it.  When a heat exchanger fails or cracks, the breathable air can be mixed with flue gases which can be poisonous, pose a serious health risk, and can be fatal.

How, When, Why do Heat Exchangers Fail:

There are many variables as to how heat exchangers fail, however the most common reasons found within the industry are use, flaw in design, and oversized equipment.

When a crack occurs is not an exact science, however most will be found between 10-20 year old equipment.   The major contributor to why in our area is use.  The metro area averages 1,000 and up to 1,500+ heating hours annually.  It is safe to assume the amount of expansion and contraction on our heat exchangers is much higher here, than the rest of the country. 

Nationally, many studies conclude that either oversized equipment, lack of maintenance, and poor air flow are the main contributors to why heat exchangers fail.

Equipment used to find Heat Exchanger Cracks:

“Any visible crack or hole discovered by using these tools is reason for requiring the heat exchanger or furnace be replaced.”  – American Gas Association

  • Infrared Video Camera with snake (most common).
  • Combustion Analyzer Kit.
  • Digital Manometer.
  • UV tracing solution, goggles, and flashlight.
  • Inspection Mirrors.

Bonfes Policy on cracked heat exchangers:

Any heat exchanger found to have a crack will result in shutting your furnace down.  It is against mechanical codes, fire department regulations, and our local utility company’s policy to allow a furnace/boiler to operate that has a cracked heat exchanger.  Most importantly, we cannot be responsible for health risks or death from carbon monoxide poisoning. 

We take these matters very seriously.  Upon request, Bonfe will even provide a second heat exchanger expert to assess the crack at no additional charge.  Return trips to prove a crack in front of the competition is at no additional charge as well.  If we are ever wrong, we will refund all trip charges, inspection fees, and give you a $100 Visa gift card.

Note:  Carbon Monoxide Detector is not an acceptable solution for a bad heat exchanger.