Be Sure You Know How Your HVAC Ignition Works for Your Unit

HVAC IgnitionThe HVAC ignition process is what fires up the furnace that keeps you warm in the winter. While an electric furnace doesn’t require ignition, gas-fired models need some method to ignite gas flowing through the burner. Typically, a signal from the thermostat initiates the flow of gas, and HVAC ignition occurs to generate heat and achieve the programmed thermostat setting. In today’s furnaces, one of three methods is utilized for HVAC ignition:

  • Standing pilot light. It’s the old-school method of igniting a furnace, but it’s still getting the job done in many furnaces today. A pilot light is simply a very small gas flame that burns natural gas continuously. When the thermostat signals for heat, the main burner gas valve opens and the flow of gas is ignited by the pilot flame. After the thermostat’s temperature setting is reached, the furnace valve closes and the burner is extinguished. However, the pilot light continues to burn continuously.  One of the reasons why pilot lights have been replaced is continuous gas consumption, burning typically 600 to 800 BTUs of gas in a 24-hour period.
  • Intermittent pilot light. This is similar to a conventional pilot light, except the flame turns off between heating cycles. When the thermostat signals for heat, an electronically generated spark lights the pilot. As the main gas valve opens, the pilot light ignites the burner, then remains lit for the duration of the heating cycle. When the temperature setting is reached, the thermostat shuts off gas flowing to the burner and the pilot light.
  • Hot-surface ignition. Today, this is the most prevalent method of igniting a gas furnace, as the system uses a fork-shaped ceramic element connected to electric wiring and positioned at the gas burner.  When the thermostat signals for heat, the gas valve opens and electrical current flows into the ceramic heating element, which instantly glows red hot. This hot surface ignites the burner without a pilot flame and without the additional gas consumption.

Consult Paitson Bros. about any issues relating to HVAC ignition components. We’ve been here with accurate information and experienced service for Terre Haute residents for the past century.

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    Jeff Paitson Jeff Paitson is a third generation business owner who continues to run the business with the same values that have been passed down from previous generations since 1922.

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    Ethan Ethan Rayburn is a lifelong resident of Terre Haute and a 2005 graduate of Purdue University.

    An Eagle Scout, Ethan spent four years as a non-profit executive with the Boy Scouts of America before joining Paitson Bros. as a comfort advisor and later General Manager. In that role, Ethan has brought a renewed enthusiasm for customer care, integrity, value, and service to Paitson Bros. Heating & Air Conditioning.

    Ethan enjoys singing and was a member of the Purdue Varsity Glee Club. He also enjoys playing and coaching soccer, spending time with his family and two young boys, and volunteering his time and resources with his church, Terre Haute First Baptist Church, which he has attended from a very young age.
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