At what water pressure does a boiler pressure relief valve discharge?

At what water pressure does a boiler pressure relief valve discharge?

• A. 15 PSI
• B. 30 PSI
• C. 45 PSI
• D. 60 PSI

Answer: (B)

A boiler pressure relief valve opens to prevent overpressure by venting water when the system pressure reaches its set point. For most residential hydronic boilers, that set point is about 30 psi. The system operates at a lower pressure most of the time, often around 12–20 psi, but the valve needs a safety margin, so it activates around 30 psi to relieve pressure before it becomes dangerous. If the pressure climbs higher, the valve continues to vent to bring it back down. The other pressures listed are not the standard safety setpoints for typical residential boilers.

A boiler pressure relief valve opens to prevent overpressure by venting water when the system pressure reaches its set point. For most residential hydronic boilers, that set point is about 30 psi. The system operates at a lower pressure most of the time, often around 12–20 psi, but the valve needs a safety margin, so it activates around 30 psi to relieve pressure before it becomes dangerous. If the pressure climbs higher, the valve continues to vent to bring it back down. The other pressures listed are not the standard safety setpoints for typical residential boilers.