🔍 Key Concepts

• Boiler safety interlocks and what they are designed to protect • The primary purpose of a flame scanner in an automatic combustion control system • What must happen automatically when a flame failure occurs in a firing boiler

💭 Think About

• Ask yourself: if the flame suddenly goes out while fuel is still being supplied, what is the most immediate danger, and what action must occur to prevent it? • Which option describes a direct, automatic protective action linked specifically to flame failure, rather than a general safety or efficiency function? • Does the flame scanner usually control efficiency (fine-tuning) or act mainly as a safety device that triggers a shutdown response?

✅ Before You Answer

• Verify which choice is directly tied to loss of flame and prevents continued fuel flow into the furnace. • Check which options talk about efficiency control versus emergency shutdown; flame scanners are primarily about safety, not fine adjustment. • Confirm that the selected option involves stopping the hazardous condition at its source (what creates and feeds the flame).