What condition would prevent a burner from continuing operation in a gun type oil burner?

The condition that would prevent a burner from continuing operation in a gun-type oil burner is related to flue temperature being too high. When the flue temperature exceeds safe operational limits, it indicates that the burner may be producing excessive heat, potentially leading to overheating, equipment damage, or even safety hazards such as fire or explosion risks. Oil burners are designed to operate within specific temperature ranges, and if the flue gas temperature rises beyond a certain threshold, the safety controls will often shut down the burner to prevent damage and ensure safe operation.

In contrast, other conditions such as low voltage could cause operational issues but may not necessarily result in an immediate shutdown like high flue temperatures would. Similarly, fuel contamination could lead to inefficient burning or other operational problems, but it would not directly cause a burner to stop functioning instantly. A blocked air intake could affect combustion efficiency and lead to operational issues as well, but again, it might not trigger an immediate shutdown compared to the critical safety risk presented by high flue temperatures.