Understanding how your HVAC and water heater operate is part of home ownership. One component that varies from system to system is the type of pilot light. Most newer models use an Electronic Ignition System (or automatic) while older models likely have a standing pilot light. Here, we explain both while quantifying the benefit of automatic.
Standard pilot lights are special valves that allow a flame to burn 24/7. When the furnace calls for heat it uses the already existing flame to light its burners. Although proven safe and reliable over many decades of use, standard pilot lights aren’t without issue. The valve can become corroded or clogged causing the flame to go out. This requires a thorough cleaning and for the flame to then be relit in order to restore functionality to the furnace. No gas should escape when the flame goes out as the valve should automatically close. Nevertheless, you should never ignore even the faintest smell of gas!
Conversely, Electronic Ignition Systems furnish a flame (or spark) only at the moment it is required. Built-in flame sensors ensure the burners are lit properly. If not, the flame sensor calls for another try. Problems arise when, after several tries, the burners still don’t ignite. In this case, the system will go into ‘lock-out’ mode for at least an hour. This is a safety feature that prevents the dangerous build-up of gas.
The reliability and safety of Electronic Ignition Systems has been accepted to the point where they are the norm in new models. Electronic Ignition Systems are maintenance free and more cost effective than standard (manual) pilot lights. Generally, each pilot light running 24/7 costs about $5 per month in fuel usage. Perhaps this is not a reason to upgrade to an Electronic Ignition System in and of itself, but it certainly is a measurable nudge!