If your home uses a gas furnace, you probably already know that you generate heat through a combustion process involving natural gas and oxygen. But, how does your furnace start this process? In the past, gas furnaces used always-on pilot lights. These small flames burned year-round, providing the "spark" necessary to ignite the main burners when a thermostat requested heat.
Modern furnaces do away with this relatively inefficient use of gas, replacing always-on pilot lights with on-demand ignition elements. These ignition elements are ubiquitous in modern furnaces, so there's a good chance you have one in your home if your furnace isn't several decades old.
Understanding On-Demand or Electronic Ignition
On-demand ignition systems (also commonly known as electronic ignition systems) provide a more efficient way to get your furnace running. An always-on pilot light must consume natural gas throughout the year, even when you're not using your heat. While you can turn your pilot light off over the summer, you'll need to reignite it before you can begin using your furnace again.
Electronic ignition systems get around this problem by using resistive heating to ignite your main burners. These elements work by passing an electrical current through an incredibly high resistance material. As the current passes through this material, it generates "waste" heat well over 1000 degrees Fahrenheit, providing the initial heat necessary to start your burners.
These ignition systems require less energy and less maintenance than traditional pilot lights, but they can also be a source of problems with your furnace. A failed electronic ignition can cause your furnace to take longer to ignite or prevent it from turning on at all.
Recognizing Issues With Your Furnace's Ignition
This particular style of electronic ignition must endure some relatively extreme conditions inside your furnace. The resistive heating element can reach scorching temperatures, straining the material over time. Additionally, it's important to remember that the purpose of this element is to ignite your furnace. The result is exposure to a gas flame every time your furnace turns on.
In most cases, the symptoms of a failing igniter are hard to miss. If the igniter has entirely failed or broken, your furnace won't turn on at all. A furnace that takes too long to ignite or intermittently fails to ignite may also have an issue with its electronic ignition. In either case, you'll need to replace the igniter to resolve the issue.
While electronic ignition systems can be brittle and tend to fail eventually, premature failure can be a sign of a problem elsewhere in your system. If you suspect your igniter is failing, it's often a good idea to have an HVAC technician examine your system to determine if there are any other issues at play. This simple step can help your new igniter last for much longer.
For more information, reach out to a company in your area that offers home heating services.