Relight your water heater pilot by turning the gas knob to off and waiting 5 minutes for residual gas to clear. Turn the knob to pilot press and hold the pilot button then click the igniter. Hold the pilot button for 60 seconds after the flame appears then release slowly. Turn the knob to on and set your desired temperature. If the pilot won’t stay lit the thermocouple likely needs replacement. Always ventilate the area before attempting to relight.