When should a cad cell be cleaned to maintain optimal performance?

Cleaning a cad cell before each heating season is important for maintaining optimal performance in oil heating systems. The cad cell, also known as a cadmium photoelectric cell, functions by detecting the presence of a flame. If the cell becomes dirty or obstructed by soot and other contaminants, it may fail to accurately detect the flame, leading to operational issues or unsafe conditions.

Cleaning it before the heating season ensures that it is functioning properly once the heating demand increases. This maintenance step helps to prevent potential system failures during the cold months when the heating system is most needed. A clean cad cell enhances the efficiency of the system by ensuring it can reliably sense the flame, which aids in proper combustion and helps to avoid problems like incomplete combustion, which can lead to increased emissions and wasted fuel.

In contrast, the other options suggest cleaning intervals that may not align with the typical usage patterns and potential buildups of soot. A monthly cleaning may be excessive unless specific conditions warrant it, while every six months may leave the system vulnerable during the peak heating months. Cleaning only when malfunctions occur could lead to unsafe operation, as issues might develop unnoticed before the heating season begins. Thus, the best practice is to proactively clean the cad cell before heating begins each year.