What should be the draft reading over the fire for a flame retention, residential oil burner?

The correct draft reading over the fire for a flame retention, residential oil burner is typically around -0.02 inches of water column. This negative draft measurement indicates that there is a slight negative pressure over the burner, which is essential for proper combustion and efficient operation of oil burners. The primary purpose of maintaining this draft level is to ensure that flue gases are effectively vented out of the combustion chamber while preventing any backflow of combustion gases into the living space. A draft reading at -0.02 helps to optimize the burner’s performance, leading to better fuel efficiency and lower emissions.

The values around -0.01, -0.03, and -0.04 inches may indicate different operating conditions that are generally not considered optimum for residential oil burners. For instance, a draft reading that is too low might not adequately remove combustion gases, while a reading that is too high could indicate excessive air leakage, which can lower efficiency and affect combustion quality. Maintaining the -0.02 reading is, therefore, crucial for safety, efficiency, and proper burner operation.