A gas furnace ignition device that is fragile and sensitive to vibration is known as what?

The gas furnace ignition device that is fragile and sensitive to vibration is the spark igniter. Spark igniters create a spark to ignite the gas in the furnace, and their construction typically involves materials that can easily be damaged by shocks or vibrations. This sensitivity means that care must be taken during installation and service to avoid damaging the igniter.

In contrast, a hot-surface igniter consists of a ceramic element that glows when heated, and although it can be fragile, it is generally more resilient to vibrations than a spark igniter. Flame sensors and thermocouples serve different functions; both are used for safety and operational sensing rather than ignition and are not specifically sensitive to vibration in the same way as a spark igniter.