Heat Exchanger

Damaged Heat Exchanger

Recently, one of Frigi-Temp’s HVAC service professionals found a heat exchanger that was blown apart in two sections. This is an uncommon manner for a heat exchanger to fail. The standard life cycle of a heat exchanger in NC is approximately 10 years. The most common way heat exchangers fail is by rusting and cracking along their welded seams.  When this happens combustion gases can mix with breathable air which creates a carbon monoxide concern for a building’s occupants. In this specific occurrence, our service team member recognized that the way this heat exchanger failed was atypical and that further diagnostics were needed.

As a rule, anytime something fails, a good technician will attempt to answer the question: “Why?” When Frigi-Temp received a “no heat” call from our customer, the first thing the technician on site noticed was that the equipment safeties caused the control board to lock out. A component known as the ‘roll out switch’ had tripped indicating high heat in the burner area. The service professional reset the control and observed the furnace start and run in heat. The combustion exhaust motor came on and ran, the gas valve opened, and the ignitor lit the burner assembly as we would expect. However, after only a few moments, the technician could see that the flame was not clean, blue, and blowing directly into the center of the heat exchanger tubes. Instead, it was distorted, had orange flame mixed with blue, and was not blowing fully into the opening of the heat exchanger. The system was then shut off to allow for a safety inspection to be performed.

Equipment panels were removed, and the blown heat exchanger was exposed. The system was installed by another service provider in 2012 and was in overall good condition. Other than the two sections that broke apart, the heat exchanger was also in relatively good condition. Frigi-Temp’s service professional explained that this type of failure was not normal, showed the customer pictures and video of the issue and the customer approved further diagnostics to determine the root of the failure.

Frigi-Temp’s team continued their investigation by checking for air flow restrictions, proper belt tension, and proper incoming gas pressure. All these things were found to be within expected parameters. When our team member checked the gas pressure at the outlet of the gas valve, the issue was found: the valve had failed.  It was allowing too much gas into the burner assembly and, in turn, the heat exchanger. Following Frigi-Temp’s best practices for diagnostics allowed our service team member to isolate the cause of the broken heat exchanger while providing an excellent customer experience.

There are many things that went right in this short scenario. First, and most importantly, the equipment safeties worked as designed and shut the equipment off when it malfunctioned. This automated shut-down protected against carbon monoxide risks and a long list of other dangers that can be associated with an overzealous gas valve. Second, Frigi-Temp’s best practices were used during the diagnostics.  This means that the technician properly went down a checklist of procedures to approach the problem efficiently with meticulous precision.  He took time to educate the customer and, in turn, the customer felt confident in our technician’s ability to make the best decision for this unit.

Frigi-temp solves issues like this for our customers every day.  Situations like this prove the importance of choosing a mechanical company that you can trust to maintain your equipment. If you are in need of a true partner for mechanical and refrigeration service and maintenance, make sure you call the Frigi-Temp team!