At what pressure are residential steam boiler relief valves typically set?

Residential steam boiler relief valves are typically set at 15 psi. This standard pressure is established to ensure safety in residential heating systems. When a steam boiler operates, the water inside is heated to produce steam, which increases pressure. If the pressure exceeds the rated capacity of the boiler, there is a risk of a hazardous situation, including potential damage to the boiler or leaks.

The relief valve serves as a critical safety device designed to release excess pressure automatically, preventing dangerous situations. Setting the valve at 15 psi is effective for most residential applications, allowing for normal operational pressures while providing a safety margin to prevent overpressure scenarios.

Other pressures mentioned in the choices, such as 10 psi, 20 psi, or 25 psi, may not align with the standard operational safety margins for residential steam systems. For instance, 10 psi might be too low for standard operation, whereas 20 psi or 25 psi could pose a risk, as the system could operate dangerously close to these limits without adequate protection. Thus, 15 psi is the industry-accepted setting for optimal safety and functionality in residential steam boilers.