Which boiler type uses a glass sight gauge to indicate water level?

Which boiler type uses a glass sight gauge to indicate water level?

• A. Hot water boiler
• B. Steam boiler
• C. Condensing boiler
• D. Electric boiler

Answer: (B)

The glass sight gauge is used to visually show the water level inside a steam boiler. In steam boilers, there’s a clear interface between water at the bottom and steam above, so operators rely on a visible indicator to maintain the proper water level—critical for safe operation and efficient steam generation. A sight glass directly shows where the water line sits inside the boiler, making it the typical method in steam boiler designs. Other types, like hot water, condensing, or electric boilers, usually use sealed systems with sensors or gauges instead of a glass sight gauge, so their water level isn’t read from a visible glass.

The glass sight gauge is used to visually show the water level inside a steam boiler. In steam boilers, there’s a clear interface between water at the bottom and steam above, so operators rely on a visible indicator to maintain the proper water level—critical for safe operation and efficient steam generation. A sight glass directly shows where the water line sits inside the boiler, making it the typical method in steam boiler designs. Other types, like hot water, condensing, or electric boilers, usually use sealed systems with sensors or gauges instead of a glass sight gauge, so their water level isn’t read from a visible glass.