What is a packaged boiler?

A packaged boiler is designed to be shipped as a complete, factory-assembled unit that includes all necessary components and fittings for operation. This design allows for quick installation and ease of use, as the boiler comes with integrated controls, safety features, and other essential parts already in place. The pre-assembly and testing ensure that it meets specific operational standards and regulations, making it convenient for end users who can simply connect it to fuel and water supplies upon delivery.

The other options describe characteristics that do not define a packaged boiler. While multiple combustion chambers or high-pressure ratings may apply to some types of boilers, they do not specifically refer to the packaged nature of the unit. Additionally, the definition of operating below a certain pressure does not align with what makes a boiler "packaged." Thus, the defining feature of a packaged boiler is its factory assembly with all necessary fittings, which streamlines the installation process.