Standing pilot lights were the norm for combustion furnaces for a long time, but in an effort to be safer and more energy efficient, electronic ignition was developed. Today’s furnaces come with electronic ignition, and you can upgrade a standing pilot to electronic ignition if you so desire. There are two kinds of electronic ignition, as we’ll explain below, and either one can effectively ignite your combustion furnace.
Hot Surface Ignition
Of the two types of electronic ignition, hot surface ignition is the more commonly-used. Hot surface ignition involves using a metal probe that heats, similarly to a light bulb – in fact, it will glow like a light bulb when it becomes hot enough. When the probe reaches the correct temperature, the main gas valve opens, and the hot surface igniter lights the gas, which lights the burner.
Common Problems with Hot Surface Igniters
The most common problem with hot surface igniters is that they crack. This is due to the constant heating and cooling of the metal, which eventually breaks down with usage. When the unit cracks, it isn’t able to reach the correct temperature and can’t ignite the gas. A second problem can come from handling the instrument. Oil deposits on the probe from direct contact with skin can interfere with its ability to heat, causing ignition failure.
As the name suggests, an intermittent pilot igniter works from a pilot that lights when needed versus a standing a pilot that stays lit constantly. The process starts with the thermostat cueing your furnace to being the ignition process. With an intermittent pilot, the pilot has its own small gas line that opens; an electric spark generated by a small electronic device lights the pilot. A flame sensor monitors the pilot and makes sure the pilot is viable; once the flame sensor detects that the pilot is viable, the sensor allows the main gas valve to open, and the intermittent pilot ignites the gas for the burners. Once all the burners are lit and running, the small gas line for the pilot turns off and extinguishes the pilot.
Common Problems with Intermittent Pilots
Positioning is important with intermittent pilots; if the pilot is too far away from the electronic device, the spark won’t light it. Additionally, if the pilot nozzle is dirty, the gas may not flow correctly, and the pilot can’t light. Should there be a problem with the electricity flowing to the electrical device, there won’t be a spark to light the pilot.
Ignition is a serious process, and if your furnace isn’t lighting because something is wrong with the electronic ignition, it’s time to call for heating repair service. The trained technicians at JW Heating & Air can handle any heating repairs in Los Angeles, so call us today!