What is the recommended action to check the water level on a boiler?

To ensure the accuracy of the water level in a boiler, performing a blowdown of the gauge glass is an essential procedure. This action helps to clear any sediment or buildup that may obstruct the proper reading of the water level by purging a small amount of water and steam from the gauge glass assembly. By doing this, you confirm that the gauge glass accurately reflects the boiler's water level. Accurate readings are critical for the safe operation of the boiler, as incorrect water levels can lead to dangerous situations, such as low water conditions that could result in overheating or even a boiler explosion.

While using the water level alarm can provide an alert for low or high water levels, it depends on the sensor functioning correctly. Inspecting the external water tank provides information about the overall water supply but does not directly verify the water level within the boiler itself. Checking the sight glass visually is important, but it can be misleading if any contaminants are present or if the glass is dirty, which is why performing a blowdown is a more reliable method.