Which type of boiler has its heating element immersed in the water?

An immersion boiler features its heating element submerged directly in the water, which allows for efficient heat transfer to the water surrounding it. This design enables rapid heating of the water as the heat produced by the element directly interacts with the water molecules. As the boiler heats the water in this manner, it can quickly reach the desired temperature, making it suitable for applications that require hot water on demand.

The ability of immersion boilers to provide quick heating is particularly advantageous in residential and commercial settings where consistent hot water supply is essential. By placing heating elements directly in the water, these boilers also benefit from simplified designs and reduced external components compared to other boiler types, allowing for easier maintenance and safety assessments.

In contrast, fire-tube and water-tube boilers rely on different mechanisms to heat the water, with fire-tube boilers having hot gases flowing through tubes that are surrounded by water, and water-tube boilers using heated water or steam flowing through tubes that run through a heated chamber. Electric boilers may use various configurations, but they typically do not feature immersed heating elements as their primary design.