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Furnace Components: A Guide for Homeowners

Furnace Components: A Guide for HomeownersWinter in Yuma takes a toll on the efficiency of your furnace. If your system hasn’t been tuned up recently, you could experience common operating problems. Understanding the main components of your unit and how they relate to the others can help you troubleshoot minor problems or communicate with an HVAC professional if service is needed.

A furnace doesn’t have many moving parts, but it’s a complex machine with interrelated components. If one component isn’t operating efficiently, it’ll affect the performance of the others.


The thermostat monitors the temperature in your rooms. When the temperature dips below the setting, the thermostat communicates with the furnace, and gas enters the burners. The pilot light ignites the gas.


The blower kicks on and brings in cool air from the cold air return, which is the duct that sits opposite the main unit, next to the filter compartment. The cooled air moves through the filter before it enters the body of the furnace.

Heat Exchanger

The heat exchanger is a metal chamber that contains liquid that heats up. The heat exchanger becomes hot, and cool air enters the system, moves around it, and warms up.


The warm air moves to the plenum, which is the large metal box on top of the unit. From the plenum, the air is sent through the ductwork and into your rooms through the registers.


The flue is the round pipe that moves combustion gases outside through the roof or a wall.

Maintaining Your Furnace

Annual preventive maintenance is crucial for keeping your heating system in good shape. It helps to:

  • Prevent common operating problems.
  • Extend the life of your system.
  • Reduce carbon emissions.
  • Improve comfort.
  • Increase efficiency.
  • Lower your energy bill.
  • Ensure safety.

An annual tuneup is inexpensive and includes a long list of tasks to restore efficiency and prevent breakdowns, such as tightening electrical and gas connections and testing the controls.

For more information about how a tuneup can improve the function and efficiency of your heating system, please contact us at Hansberger Refrigeration and Electric Company, proudly serving the Yuma area.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about furnace components and other HVAC topics, download our free Home Comfort Guide or call us at 928-723-3183.

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