The gas furnaces manufactured today are substantially more energy efficient than furnaces manufactured 15 to 30 years ago. In fact, today’s furnaces are available with up to a jaw-dropping 99 AFUE (Annual Fuel Utilization Efficiency), which means the furnace converts 99% of burned fuel to heat energy for the home. An important component of higher energy-efficiency ratings in modern furnaces is the gas furnace igniter. Read on to learn how this simple yet important device works.
From Pilot Light to Electronic Igniters
It wasn’t that long ago that gas furnaces used a standing pilot light to ignite gas for furnace heating. The pilot light was always on whether the furnace was in use or on standby. This also meant that the gas line was always on. The constant pilot light wasted energy and could leak gas into the home if backdrafting occurred.
Gas furnace igniters have all but replaced standing pilot lights. The two types of gas furnace igniters are intermittent pilot and hot-surface ignition.
- Intermittent pilot. An intermittent pilot igniter generates a high-voltage electrical spark that ignites a gas pilot, which then lights the burners.
- Hot-surface ignition. Hot-surface ignition utilizes an electrical-resistance heating element to ignite the furnace burners.
Troubleshooting Gas-Furnace Ignition
If the hot-surface igniter fails to heat up or the intermittent pilot fails to spark, you’re not going to have any home heating. So, it can be useful information to know how to identify furnace-ignition problems for troubleshooting or, better yet, to call your HVAC technician.
- Damaged igniter. Electronic igniters should last anywhere from four to seven years.
- Temperature limit switch. If the furnace temperature gets too high, a limit switch will turn off the igniter. The furnace will need to be reset to start again.
- Incorrect installation. The correct voltage for the igniter must be used or it will fail.
- Power surge. A power surge can damage a hot-surface igniter.
For more information about a gas furnace igniter or to schedule HVAC service for your Dayton home, contact the HVAC experts at Detmer and Sons.