Furnace Basics: How Does a Furnace Work?

Are you a new homeowner or someone who is unfamiliar with the inner workings of a furnace? You’re not alone. It’s one of the most frequent questions we receive: how exactly does a furnace work? By having a basic knowledge of your HVAC system, you’ll be able to troubleshoot on your own, or know when it’s time to call a professional.

How Does a Furnace Work

What is a Furnace?

The most common type of furnace is a gas-powered system, which heats air in one area and then distributes it throughout the home via ductwork and vents. It is often referred to as “forced air,” and is common throughout the United States. The main parts of your furnace system include the thermostat, gas valve, burners, heat exchanger, blower, and ventilation system. When your furnace creates heat, combustion gases are vented out of your home via a flue pipe. 

How Does a Furnace Operate?

Your furnace starts when it receives a signal from the thermostat that tells it to turn on. Depending on the temperature you set, when the thermostat detects the air temperature dropping below that number, it activates the furnace. The gas valve opens and ignites the burner component beneath the combustion chamber. The gas valve works with the thermostat to regulate the amount of gas that flows into your furnace.

After gas is released, the flames heat a metal heat exchanger, circulating the heat through tubes and transferring the warmth to the blowing air.

How Does the Air Move Through a Furnace?

As the heat circulates, the blower motor fans the heat through the ductwork in your home. Once it warms the various rooms through each vent, the thermostat is notified of the increased temperature which shuts off the furnace until the temperature declines again. 

We hope this paints an easy picture of what the inner workings of a furnace look like and how it functions to provide heat to your family. If you have any questions about your furnace or are concerned it is not working correctly, don’t hesitate to reach out to one of Baylor’s experienced team members.

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