See How Solar Looks On Your Home Read More

Skip navigation

Serving The Greater Fresno Area Since 1970

Serving The Greater Fresno Area Since 1970


Donald P. Dick Air Conditioning Blog

Learn How Your Furnace Works Now — You Might Be Tested Later

Learn How Your Furnace Works Now -- You Might Be Tested LaterNo one is likely to show up at your home and hand you a quiz on how your furnace works. However, if your heating system malfunctions, you’ll definitely be tested – in your patience, your troubleshooting knowledge, and your ability to determine when it’s time to call in a professional. Here’s a basic description of how your furnace works to make it easier for you to “pass” these tests.

Most home heating systems consist of five interrelated parts:

  1. One or more thermostats for controlling temperature levels and furnace operation.
  2. The furnace unit that heats the air that warms your home.
  3. An air handler or blower that distributes the air throughout your home.
  4. Supply ducts that carry warm air from your furnace to your home’s interior.
  5. Return ducts that bring expended air back to the furnace to be heated and distributed again.

The heating cycle begins with the thermostat, where you set the temperature you want for your indoor environment.

When the temperature inside your home drops below set levels, the thermostat activates the furnace and the burner. Controlled flames ignite inside the furnace, generating heat collected by a heat exchanger. Fuel-burning furnaces use natural gas, fuel oil or propane to generate heat. Less common electric furnaces generate heat using a series of powerful heating elements or coils.

When the furnace comes on, a fan blows air across the heat exchanger. The air absorbs heat and is then sent into the supply ductwork, where it’s distributed to every area of your home where the ductwork reaches. The warm exits from a vent or register, heating your living spaces.

The return ductwork draws cooled air back into the system, circulating it to the furnace unit where it will be filtered, reheated and recirculated. The cycle continues until the thermostat detects that the inside temperature settings have been reached. The thermostat then shuts off the furnace until indoor temperatures drop again and the cycle repeats.

Donald P. Dick Air Conditioning has almost four decades of experience serving the HVAC needs of customers in Fresno and the surrounding communities. Contact us today for more information on how your furnace works or for expert, professional repair service when it doesn’t.

Our goal is to help educate our customers in the greater Fresno, California area about energy and home comfort issues (specific to HVAC systems).  For more information about furnace and other HVAC topics, download our free Home Comfort Resource guide.

Image courtesy of Shutterstock

Comments are closed.