What is the function of a relief valve on a water heater or a boiler?

Answer by  worker1744 (141)

Relief valves on water heaters and boilers will release excess pressure, or steam in a safe loacation in order to avoid damage to the unit, or harming nearby people.

Answer by  jargon (112)

Heated water expands and creates internal pressure. A relief valve opens automatically at a certain pressure to prevent internal build-up beyond a set point. This prevents the unit from rupturing.

Answer by  Tiny1234 (115)

The valve is there in case the boiler overheats and builds up too much pressure. The valve opens letting the pressure escape and preventing the boiler from exploding. A Good Thing!

Answer by  mako (289)

Pressure relief valves are used to relieve excess to dangerous pressures caused my malfunctioning water heaters. They contain valves that open automatically according to a set or designed pressure. The outlet of a relief valve is attached to a pipe that leads to an inside or outside drain. This prevents costly water damage inside the home.