Which type of boiler is specifically designed to be factory assembled with all necessary fittings?

A packaged boiler is specifically designed to be factory assembled with all necessary fittings, making it a convenient choice for installation. These boilers arrive at the job site as a complete unit, which means that all essential components such as the burner, controls, and safety devices are pre-installed and tested during manufacturing. This factory assembly not only speeds up the installation process but also reduces the amount of on-site labor and potential installation errors.

Moreover, packaged boilers are designed for efficiency and safety since they undergo rigorous testing before leaving the factory. This ensures that they meet the required codes and standards, which may vary based on location and intended use. By opting for a packaged boiler, users benefit from a standardized and streamlined system that can be easily integrated into existing setups or used in new construction.

In contrast, high-pressure boilers are characterized by their ability to operate at pressures above 15 psi, and while they may be packaged, they do not exclusively represent the concept of a factory-assembled unit. Externally-fired boilers utilize combustion sources outside of the boiler itself, which affects their design and assembly approach. Manual boilers require a significant amount of manual intervention for operation and may not have the same level of factory assembly or integration as packaged units.