In what scenario might the cad cell fail to operate correctly?

A cad cell, or a flame sensor, is designed to detect the presence of a flame in an oil burner system through light detection. It generally works by monitoring the infrared light produced by the flame; if the flame goes out or is too weak, the cad cell may not receive sufficient light to confirm that combustion is taking place.

In the context of the answer regarding inadequate light detection, this scenario is significant because if the cad cell does not detect the necessary light levels, it will not function correctly, leading to a failure in the burner operation. This can occur due to several factors, such as soot buildup on the cad cell lens, a flame that is too weak or flickering, or improper positioning of the cad cell away from the flame.

The other scenarios, while they may impact boiler or furnace operation, do not directly relate to the core function of the cad cell. For instance, a flame color change could indicate a combustion issue but doesn’t inherently affect the cad cell's ability to detect light as long as there is still adequate light in the infrared spectrum. Temperature fluctuations could influence efficiency or operation but do not typically impair the cad cell's functionality directly; the sensor responds to light intensity rather than temperature. Excessive pressure may lead to operational