Your furnace’s ignition system plays a big part in ensuring that your heating system operates efficiently and safely. Without a properly functioning ignition system, your furnace won’t be able to start or provide the heat your home needs. There are two main types of ignition systems commonly used in modern furnaces: the standing pilot light and the electronic ignition system. Absolute P&M Services would like to explore these different types of ignition systems, how they work, and the signs that they may be failing.
Standing Pilot Light Ignition System
The standing pilot light is one of the oldest and most traditional types of furnace ignition systems. It features a small flame that remains lit continuously, even when the furnace is not actively heating. This flame serves as the ignition source for the burner when the thermostat signals the furnace to turn on. When the thermostat calls for heat, the gas valve opens, allowing gas to flow to the burner. The standing pilot light then ignites the gas, producing the flame that heats the air, which is then circulated throughout your home.
Electronic Ignition Systems
Electronic ignition systems are more modern and energy-efficient than the standing pilot light system. There are two primary types of electronic ignition systems used in furnaces today, the intermittent pilot ignition system and the hot surface ignition system.
Intermittent Pilot Ignition System
The intermittent pilot ignition system is an upgrade from the traditional standing pilot light. Unlike the standing pilot, this system only ignites the pilot light when the furnace is called to heat, meaning it doesn’t waste energy keeping the pilot light burning constantly. When the thermostat calls for heat, an electronic spark ignites the pilot light, which then lights the burner. Once the desired temperature is reached, the pilot light automatically shuts off, conserving energy.
Hot Surface Ignition System
The hot surface ignition system is one of the most energy-efficient types of ignition systems used in modern furnaces. It eliminates the need for a pilot light altogether and instead uses a heating element to ignite the burner. When the thermostat calls for heat, an electric current passes through a silicon carbide or silicon nitride heating element, which heats up to a very high temperature (usually around 1,800°F). This hot surface igniter then ignites the gas that flows into the burner, producing the flame needed to heat your home.
Common Causes of Ignition System Failure
Regardless of the type of ignition system your furnace uses, there are several common reasons why an ignition system might fail. Here are some typical causes:
• Dirty Components: Over time, dirt, dust, and debris can accumulate on the ignition system components, such as the pilot light, burners, or hot surface igniter.
• Faulty Thermocouple: In standing pilot light systems, the thermocouple is a safety device that shuts off the gas supply if the pilot light goes out or won’t stay lit.
• Worn or Damaged Igniter: In electronic ignition systems, the igniter can wear out over time due to the high temperatures it generates and will need to be replaced.
• Gas Supply Issues: If the furnace isn’t receiving enough gas to fuel the ignition system, it won’t be able to ignite properly. Low gas pressure, a blocked gas line, or a malfunctioning gas valve can all lead to ignition problems.
• Electrical Issues: Faulty wiring or electrical connections can prevent electronic ignition systems from functioning properly. If the furnace isn’t receiving the necessary power, the ignition system won’t work.
What to Do If Your Furnace Ignition System Fails
If you notice any of the signs of ignition system failure, it’s essential to address the issue as soon as possible to avoid a complete furnace breakdown or safety hazards like gas leaks. Here’s what you should do:
• Turn Off the Furnace
• Check the Pilot Light
• Contact a Professional Technician
• Schedule Regular Maintenance
Central Forced Air Furnace Heating Maintenance, Repairs, Replacement & More in Santa Fe, Tomball, Sugar Land, Galveston, Austin & Greater Houston, Texas
The ignition system is a vital component of your furnace, ensuring that your home stays warm and comfortable during the colder months. Whether your furnace uses a standing pilot light or an electronic ignition system, understanding the signs of failure can help you address issues before they become serious problems. For help restoring your home’s heating system, contact Absolute P&M Services today.
