What is the purpose of a temperature and pressure relief valve in a gas water heater?

The temperature and pressure relief valve in a gas water heater serves a critical safety function by preventing excess pressure from building up in the tank. When water is heated, it expands, and if the pressure within the tank exceeds safe limits, it poses a risk of tank rupture or explosion. The relief valve is designed to open automatically when either the temperature or pressure exceeds preset levels, allowing steam or hot water to escape safely, thus protecting both the unit and the surrounding area.

While regulating water temperature and controlling the flow to fixtures are important functions within a water heating system, they are not the primary purpose of the temperature and pressure relief valve. This valve specifically focuses on safety, ensuring that the water heater operates within its designated pressure range. Turning the heater off is also not a function of this valve; instead, it is more about allowing excess pressure to escape while keeping the unit operational under normal conditions.