LP Ignitors for Heaters

LP Gas Furnaces

• When compared to natural gas-powered furnace systems, LP systems use liquid propane in the place of natural gas as a fuel source. In general, furnace systems heat a home’s air through a network of ducts and vents. Some systems may also include an air conditioning unit that works alongside the heating system.

  LP ignitors operate within a heat exchanger unit that converts cool air to warm air. When home temperatures drop below a certain point, thermostats send electrical signals to the ignitor system. Once lit, the ignitor lights the furnace burners. Blower devices then circulate warm throughout the home.

Standing Pilot Systems

• Older model LP heaters typically use a standing pilot light system as the ignitor component. A standing pilot light remains on at all times. This system uses a controller knob and thermocouple device. The thermocouple receives signals from a home’s thermostat and sends electrical currents to the controller knob. When indicated, the controller knob releases propane gas while a blower device pushes the gas across the standing pilot light. This series of events causes the furnace burners to light and warm the air that moves through the heat exchanger unit.

Electronic Pilot Systems

• Electronic-powered pilot ignitors are included on most newer model heater systems. Electronic ignitors include either a hot surface ignition device or an intermittent pilot device. Hot surface ignitions work similarly to the way an electric current moves through a light bulb filament. In this case, the electric current ignites the pilot. With an intermittent pilot device, a high voltage spark causes the pilot to ignite. With both devices, a flame sensor mechanism triggers the lighting of the burner compartment.

Effects

• The transition from standing pilot systems to electronic ignitor systems has resulted in increased energy efficiency on the newer model furnaces. The Preferred Home Repair & Services reference website reports that newer electronic ignitor systems enable furnaces to meet or exceed government levels for energy efficiency. In effect, the standing pilot light systems consume gas on a continuous basis since the pilot remains lit at all times. In addition, standing pilots require specific combustion conditions before they'll light. Improper conditions can produce a weak or low flame, which can cause problems within the heat exchanger and burner compartment areas.