What is the pressure safety relief valve maximum setting for an under fired residential water heater?

The maximum setting for the pressure safety relief valve on an under fired residential water heater is 150 PSIG. This standard is established to ensure safety and prevent excessive pressure buildup within the water heating system. A relief valve set at this pressure is designed to operate effectively to mitigate risks such as tank rupture or failure of system components due to overpressure.

In residential water heating applications, maintaining this setting is crucial because it balances the need for safe operation with the efficient performance of the system. Pressure relief valves act as a critical safety feature by automatically releasing water when pressure exceeds this limit, ensuring that the system remains within safe operating conditions.

Higher settings, such as 210 PSIG or 212 PSIG, exceed typical safety guidelines for residential systems and may increase the risk of system failure. A setting of 100 PSIG is lower than what is commonly required for most residential water heaters.