What is a critical installation requirement for boilers regarding shutoff valves?

A critical installation requirement for boilers is that shutoff valves must be installed on both the supply and return sides of the system. This design enhances safety and ensures functionality. Providing shutoff valves on both sides enables maintenance personnel to isolate the boiler from the rest of the heating system easily. This is particularly important during repairs or servicing because it allows for safe operation and prevents potential leaks or mishaps during maintenance work.

Furthermore, having valves on both the supply and return lines aids in the effective isolation of the boiler, which is crucial in systems that may require intervention while the rest of the heating system remains operational. This requirement is typically codified in local and national plumbing and mechanical codes to ensure consistent safety standards across installations.