There was a time not too long ago that there was only one type of ignition system for furnaces. Indeed, the same kind of ignition system served pretty much every type of combustion based heating system. That system was the standing pilot light, which was used for many decades. More recently, however, there have been a number of innovations that have risen up to challenge the standing pilot light for supremacy. Let’s take a look at the different kinds of ignition systems for furnaces, and which one you should look for when installing a new one.
Standing Pilot Light
The standing pilot light is the oldest of the ignition systems, and is still used by many furnaces across the country. It consists of a small burner assembly attached to a gas line. The assembly and gas line are connected to a flame sensor called a “thermocouple.” The thermocouple keeps a valve in the gas line open as long as the flame is lit, to keep gas flowing to the flame. If the flame goes out, the thermocouple closes the gas valve as a safety measure. Standing pilot lights are always supposed to be lit, and are only out if there is a problem. While they are a fairly reliable ignition sources, standing pilot lights are not very energy efficient, and waste a lot of fuel by being lit all the time.
Intermittent Pilot Light
Intermittent pilot lights were invented in an attempt to solve a lot of the problems associated with standing pilot lights. They consist of a much more complex electrical system, instead of gas, culminating in an electrode instead of a flame. When the thermostat sends a call for heat, the electrode generates a spark that ignites the system. When not needed, the intermittent pilot remains dormant. This solves the two biggest problems with standing pilot lights: having the flame blow out and wasting energy.
Heating Element Pilots
Heating element pilots are another type of electrical ignition system. Rather than throwing off sparks to ignite the burners, however, heating element pilots use similar heating elements to a lightbulb wire. Instead of giving off light, however, most of the energy directed into the heating element is expelled as heat. This heat eventually gets high enough to ignite the gas and start the burners. This also avoids the standing pilot light’s two biggest issues. However, the actual heating elements do eventually burn out and require replacing.
If you aren’t sure what kind of ignition system would fit your furnace best, call Downtown Air & Heat. We provide furnace services throughout Orlando.
