When replacing an oil burner fan, which detail is most important?

The most important detail when replacing an oil burner fan is the size of the wheel and the rotation direction. The fan wheel's size directly impacts airflow and the overall efficiency of the burner. If the replacement fan does not match the required specifications for size, it could lead to inadequate combustion, poor heating performance, or even system damage.

Additionally, the direction of rotation is critical because a fan that rotates the wrong way will not move air effectively through the burner, compromising the combustion process and potentially causing safety hazards. Ensuring that both the size and rotation direction align with the original equipment specifications ensures that the oil burner operates safely and efficiently.

While brand compatibility is also important to ensure a proper fit and quality, it becomes secondary if the size and direction are incorrect, as those factors directly affect the performance of the system. Noise level, while a consideration for comfort and operational environment, does not impact the fan's fundamental functionality in the heating process. Finally, the type of oil being used is relevant but does not relate to the fan itself—the fan is designed to work with the specified type of burner, making the technical specifications of size and rotation paramount.