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The Importance of a Combustion Efficiency Test

A combustion efficiency test of your furnace can turn up critical issues that impact heating performance, operating costs, as well as the safety of the occupants in your home. Proper combustion efficiency in a gas-fired furnace is indicated by the relative percentage of certain gasses present in the furnace exhaust stream. A qualified HVAC service technician utilizing a combustion analyzer can sample the gasses and use that data to diagnose and repair a variety of potential problems. These issues are typically not revealed by a simple visual inspection.

Utilizing a probe inserted through a hole into the furnace exhaust vent, a digital combustion analyzer incorporates a probe to measure combustion gas data including:

  • Carbon monoxide
  • Carbon dioxide
  • Percent of oxygenization
  • Temperature of exhaust stream.

Why Is A Combustion Efficiency Test Important?

Gas analysis provides vital information about the furnace combustion process that is not available any other way. Imbalances or abnormalities in specific gasses can be a red flag that help a service technician identify issues including:

  • Excess carbon monoxide. While some carbon monoxide (CO) gas is normal in furnace combustion, levels elevated above specific safety limits are a warning sign. In the event of a cracked heat exchanger—an issue that may occur, particularly in older units—high levels of poisonous CO gas may leak into the system airflow through a crack and spread throughout the house.
  • Heating inefficiency. If the combustion gas ratio indicates high levels of unburned natural gas fuel, you’re not getting the heating performance you’re paying for in monthly operating costs. Wasted fuel means higher heating expenses for lower household comfort. A qualified technician can make adjustments such as gas flow to improve combustion efficiency.
  • Toxic emissions. Imbalances in combustion gas may also be a factor in elevated levels of sulfur dioxide. This substance is highly corrosive to furnace components and also harmful to the outdoor environment when released in the furnace exhaust.

For more information about the benefits of a combustion efficiency test of your furnace, ask the heating professionals at Beyer Boys.