What is the purpose of a pressure relief valve on hot water heaters?

The purpose of a pressure relief valve on hot water heaters is to prevent over-pressurization and potential explosion. This valve is a critical safety feature designed to maintain safe operating conditions within the hot water system. When the water heater heats water, it can create excess pressure due to thermal expansion. If this pressure exceeds the safe limit, the pressure relief valve automatically opens to release excess pressure, allowing steam or water to escape.

By doing so, the valve helps to avert dangerous situations such as tank rupture or explosion that could result from excessive internal pressure. This is particularly important in residential plumbing, where safety standards are paramount to protect both property and occupants. Thus, the presence of a properly functioning pressure relief valve is essential to ensure that the hot water heater operates safely within its designed pressure limits.