What is the normal voltage for a hot surface or glow coil igniter in a furnace?

The normal voltage for a hot surface or glow coil igniter in a furnace is typically 120 volts. This voltage is standard for residential HVAC systems in most areas, allowing the igniter to heat up sufficiently to ignite the gas in the furnace.

When the igniter is energized, it reaches a high temperature, often over 1,200 degrees Fahrenheit, and this intense heat is crucial for starting the combustion process effectively and safely. Igniters function by drawing power at this voltage level to create the heat necessary for ignition, and the 120-volt supply is widely used because it is compatible with the electrical systems common in homes.

In contrast, other voltage levels mentioned, such as 240 volts, are not typically associated with hot surface igniters in residential settings due to safety concerns and electrical compatibility issues. Lower voltages like 60 volts or 30 volts do not provide enough energy to generate the required heat for ignition. Therefore, understanding that 120 volts is the standard voltage illustrates how it supports the operational efficiency and safety of the furnace's ignition system.