Which part of the oil heat system is responsible for igniting the fuel?

The part of the oil heat system responsible for igniting the fuel is the electrode. The electrode generates a high-voltage spark, which ignites the oil mist emitted from the fuel nozzle. This ignition process is crucial for starting the combustion of oil within the burner, and without it, the system would not be able to efficiently heat the space as intended.

The fuel nozzle, while critical for atomizing the fuel oil into a fine mist to ensure proper combustion, does not ignite the fuel itself. Instead, it works in conjunction with the electrode to facilitate the ignition process. The control box manages the entire operation of the burner, including timing and safety functions, but it does not play a direct role in ignition. The flame sensor is designed to detect whether a flame is present during operation and will help monitor the combustion process, but it is not involved in the actual ignition of the fuel. Thus, the electrode is the key component that initiates combustion in the oil heat system.