What condition can cause extinction pop in a burner?

The correct choice pertains to the condition of no port loading with faster-burning gas. Extinction pop in a burner refers to a situation where the flame goes out and then reignites with a loud popping noise. This phenomenon often occurs when there is insufficient fuel supply—or, in this case, when there is no port loading—combined with the characteristics of faster-burning gas.

In the absence of adequate fuel, the burner lacks the necessary combustion mixture to sustain the flame, leading to extinguishment. Fast-burning gases require precise conditions for ignition, and if the burner isn't properly loaded with fuel, the mixture can become too lean, causing the flame to fail. Once the conditions change, for example with fluctuations in gas flow or pressure, the burner may reignite suddenly, resulting in the characteristic "pop."

Understanding burner operation and fuel dynamics is crucial for effective troubleshooting. This context helps explain why the other options may not directly lead to extinction pop. High port loading typically provides more fuel and aids in combustion, while too much primary air or open air shutters can result in a lean mixture but may not directly correlate to the abrupt condition leading to extinguishing and reignition in the same way as insufficient port loading.