If the burner is firing and there is no water in the gauge glass, what should be done?

In the situation where the burner is firing but there is no water visible in the gauge glass, it is critical to shut down the burner and secure the boiler immediately. The gauge glass is an essential safety feature that provides a visual indication of the water level in the boiler. If there is no water, and the burner continues to fire, it can lead to severe overheating, potential failure of the boiler structure, or even an explosion due to excessive pressure and temperature.

This course of action not only prevents damage to the boiler but also ensures the safety of the operating personnel and the facility. Engaging in any continuation of operation under such circumstances would pose a significant risk, as it may lead to catastrophic failure. Securing the boiler allows for proper assessment and safe handling before the situation is resolved, reassessing water levels, and conducting necessary maintenance or repairs before re-initiating operations.

The other choices might delay essential safety actions or could lead to dangerous situations. Thus, immediate shutdown of the burner and securing the boiler is the most responsible and safest choice.