When the weather turns hot and cold, the first thing we think about is our HVAC system. Many homeowners are familiar with their gas furnace but have little knowledge of how the system works. Of course, it is convenient to have a gas furnace that allows you to set your ideal temperature and forget about it. But how does it operate?

At Pioneers Heating and Air, we want every homeowner to understand how this important piece of home equipment works, and you can learn all about it right here.

Primary Parts of a Gas Furnace

Let us begin by discussing the various components of a gas furnace and how they work together to provide heat and air conditioning to your home or office.


The thermostat is an electronic device that measures and regulates the temperature of a space. It is located remotely and hard-wired to the furnace. By adjusting the setting on the thermostat, you can increase or decrease the heat produced by your furnace. This process begins when you change the thermostat’s temperature, which signals the control board inside the furnace.

Control Board

Furnace burners are small outlets that emit gas and ignite it into flames within the furnace. A furnace burner may also include a pre-mixer before the burner. Here, air and fuel mix before entering the burner, ensuring better combustion and more efficient heating from the furnace.


Furnace burners are small outlets through which gas is emitted and ignited into flames within the furnace. A furnace burner may also include a pre-mixer located before the burner. Here, air and fuel are mixed before entering the burner, ensuring better combustion and more efficient heating from the furnace.


The igniter is the device that ignites gas from gas burners. Igniters can quickly and effectively light the gas in a burner by producing sparks or hot surfaces. Other types of igniters generate heat without the use of a spark. Instead, these ignitors heat up and make contact with the gas’s surface to heat the air blown out of the furnace.

Heat Exchanger

Heat exchangers are a network of thin-walled metal tubes that direct warm air from your heater or boiler into a specific area of your home to make it feel warmer and cozy. Cold air is blown over the hot tubes to bring warmth from the heating source into the room, providing just enough heat without overworking your heater.

Blower Fan

The blower fan is a small electric fan and motor whose main function is to circulate warm air from the furnace to different rooms in the home according to the temperature set on the thermostat.

A Fundamental Understanding of the Heating Cycle

A few simple steps can explain the most fundamental process of a heating cycle. Note, though, that while these steps describe how the furnace generates warm air, they do not cover the entire process. 

  1. The burner ignites fuel source, in this case, natural gas or propane.
  2. The flame begins to heat the metal heat exchanger, and the flue expels the exhausted gas.
  3. The heat exchanger transfers the heat to the cold air inside your home.
  4. The blower then pushes the warm air into your home’s ductwork to disperse it.
  5. Warm air fills each room, while colder, denser air is drawn back into the furnace via the return ducts, where the process repeats.

The process repeats every time you raise the thermostat temperature or when the temperature in your home falls below a certain threshold. The heater then kicks back on to restore the appropriate temperature in your home according to the thermostat setting.

During this process, all the components in your furnace must function properly for your home to be properly heated. Even a single faulty part could create issues. Reduced airflow, cold air blowing, and other issues are the most common HVAC repair calls at Pioneers Heating and Air.

HVAC near Me

If you are having trouble with your furnace, Pioneers Heating and Air is ready to help. We specialize in repairing and servicing furnaces of all makes and models, including top brands such as Carrier, Goodman, and Lennox. Our expert team commits to providing you with the best heating and air conditioning service possible. We also offer a variety of heating and cooling services, such as air conditioning repair and installation, duct cleaning, and others. Call us today for dependable furnace repair services in South Pasadena, CA, and the surrounding areas.

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