A typical range for the pressure setting of an automatic fill valve (pressure reducing valve) in a hot water heating system is:

In a hot water heating system, the automatic fill valve, also known as a pressure reducing valve, ensures that the system maintains the appropriate pressure for optimal operation. The typical pressure range of 103 to 125 kPa is commonly recommended for residential and light commercial systems. This range provides sufficient pressure to fill the system and maintain water circulation without risk of over-pressurizing, which could damage pipes or components.

Maintaining pressure in this range ensures that there is adequate water movement throughout the heating system, allowing for efficient heating and distribution of hot water. Pressures that are too low could lead to inadequate circulation and potential overheating of certain components due to insufficient water flow.

In contrast, other options present pressure settings that are either too high or too low for standard applications. Higher pressures can increase stress on system components, leading to leaks or failures, while lower pressures may not provide adequate functionality for the heating system. Therefore, the chosen range is integral to ensuring both safety and efficiency in operation.