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How Does a Gas Furnace Work?

gas furnace

In this part of the country, gas furnaces are pretty common. Many homeowners know a little bit about gas furnaces, but don’t really understand how the system works. Cates Heating and Cooling wants our customers to know just how this important piece of equipment in their home works to keep them comfortable when it is cold outside.

A Basic Understanding of the Heating Cycle

The most basic heating cycle can be explained in a few easy steps.

  1. The fuel source, either natural gas or propane in this case, is ignited in the burner.
  2. The flame starts to heat up the metal heat exchanger and exhaust is sent out of the flue.
  3. The heat exchanger transfers heat to the cold air inside your home.
  4. The blower then forces the warm air into the ductwork of your home where it is distributed throughout the house.
  5. Warm air fills each room, while colder, denser air is brought back into the furnace by the return ducts to furnace where the process repeats itself.

While this does explain how the furnace produces warm air, it doesn’t cover everything in the process.

An In-Depth Look at How a Gas Furnace Works

To better understand how a gas furnace really works, let’s take a look at the infographic below:

gas furnace

  1. The thermostat allows you to control the temperature of the air in your home. When you change the temperature on the thermostat, it prompts the control board inside the furnace to begin the heating cycle. To do this, the ignition switch is turned on.
  2. The ignition switch is responsible for lighting the gas in your furnace’s combustion chamber. The gas is brought into the combustion chamber via gas jets. Then, a pilot light (in older furnaces) or a hot surface ignitor ignites the gas jets.
  3. The heat exchanger, which is a set of coils or looped metal where air passes over, is heated by the lit gas. Over the heat exchanger, air warms up as it passes over the coils or metal.
  4. The hot air is then passed into the blower, where it is pushed into the duct system of your home, where it can be delivered into each room.
  5. When your home has reached the temperature displayed on the thermostat, the thermostat shuts off the gas valve, which prevents more warm air from being pumped into your home.

The process restarts when you increase the temperature at the thermostat or when the temperature in your home drops too low and the heater kicks back on to reestablish the proper temperature in your home based on the thermostat setting.

During this process, all of the components in your furnace need to work properly for your home to be heated properly. Even one malfunctioning piece could cause problems. Reduced air flow, blowing of cold air, and other problems frequently lead to service calls at Cates Heating and Cooling.

If you are having trouble with your furnace, Cates Heating and Cooling is ready to tackle the issue. For help with your furnace, give us a call at 913-888-4470. One of our expert technicians can diagnose the issue and work with you to get it fixed as quickly as possible.

Cates Heating and Cooling also offers annual maintenance plans that can give you peace of mind that your furnace is running safely and efficiently. During these inspections, a technician will test all of the safety controls, inspect the burners and other parts, and replace air filters.

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