Which component is important for detecting flame presence in an oil burner?

The component that is crucial for detecting flame presence in an oil burner is the cad cell. This device functions as a flame sensing device that responds to the light produced by the flame. When the flame is present, the cad cell will allow the electrical current to pass through, enabling the burner to continue operating. If the flame goes out, the cad cell detects the absence of flame and interrupts the current, leading to the burner shutting off as a safety measure.

This function is vital for ensuring safe operation, as it prevents the potential hazards associated with unburned oil. The cad cell not only protects against flame loss but also contributes to energy efficiency by ensuring that the burner only operates under safe, flame-present conditions.

In contrast, the thermostat regulates temperature and is not involved in flame detection; the blower motor circulates air but has no role in monitoring flame presence; and the furnace filter serves to cleanse the air being circulated, which is unrelated to flame detection.