What device is responsible for ensuring proper fuel delivery in a burner?

The fuel pump plays a crucial role in an oil burner system by delivering the right amount of fuel from the tank to the burner. It creates the necessary pressure that allows the fuel to be injected into the combustion chamber at the correct rate, ensuring efficient and complete combustion. This is essential for optimal burner performance, as both insufficient and excessive fuel delivery can lead to issues such as incomplete combustion, inefficient heating, or even safety hazards.

The blower, while important for providing air to support combustion, does not handle fuel delivery directly. The transformer is primarily used to generate the high voltage needed for ignition, and the relay functions as a switch to control the power supply to different components. Thus, while all these devices are important in the operation of an oil burner, the fuel pump specifically governs the fuel delivery aspect, making it the correct choice for this question.