The T & P (Temperature and Pressure) valve is the water heater’s primary safety apparatus. Should the temperature and/or pressure within the tank exceed safe limits, the T & P valve is designed to release the pressure to avoid an explosion.
Testing the T & P Valve
The T & P valve should be tested annually. To test the valve, the small handle should be moved upward to the vertical position. If it is incapable of staying upright, the T & P must be replaced. Furthermore, with the heater functioning normally and with hot water therein, water should discharge through the valve.
Water heater manufacturers recommend that the T & P valve be replaced every three years (or sooner if necessary). AAA AUGER recommends that a log be kept on the heater itself (written on the tank jacket with a permanent marker) to monitor and track both annual testing and replacement intervals.