🔍 Key Concepts
• Typical boiler burner layout: main burner, air register, igniter location
• Purpose of an igniter – to light off the main fuel/air mix, often as a small auxiliary burner or spark near the furnace side
• Difference between an igniter and the main fuel nozzle/atomizer inside the burner barrel
💭 Think About
• Look at which numbered part is positioned so it can first start combustion and then ignite the main burner flame.
• Compare the size and location of each candidate number (2, 3, 7, 9). Which one looks like a small, separate lighting device instead of part of the main fuel control or diffuser?
• Trace the fuel path from the control valve toward the furnace. Which numbers are clearly in the main fuel passage, and which one sits off to the side near the furnace wall?
✅ Before You Answer
• Identify which number is on a small, separate assembly entering at an angle near the furnace wall, rather than along the main burner axis.
• Confirm that the part you pick is located right at the furnace end, where an igniter tip or flame would need to be to start combustion.
• Eliminate any numbers that point to valves, linkages, or internal burner diffusers, since those are not usually called the igniter.