The Pressure relief valve is a very important part of your water heater and in fact many plumbers would say its one of the most important parts of the water heater.
The pressure relief valve should be check at least twice a year to make sure that it is not clogged with debris and works properly and oddly enough, not that many people even check there valve until the actual water heater starts leaking and then its just too late.
The pressure relief valve is there to actually protect and it does that by opening up when the water tank reaches a certain pressure that is unsafe for operation, There is no need to worry about the setting either as the pressure relief valves are actually set to the requirements of the water heater and if or when you need to replace the valve the plumbing supply house will know how to match you old valve to the new one, so don’t panic.
Also in the picture you will see a white tube that is connected to the relief valve and that is called the drain spout and that should be set to reach a few inches before the floor and depending on the state that you live in will determine how far up from the floor that will be so make sure to check with your local plumbing code.
