Lowe's provides information regarding hot water heater maintenance on the company's official website. Checking the pressure valve and flushing the tank every six months are recommended to keep the hot water heater working properly.
The pressure relief valve is a safety device that releases pressure and prevents the tank from exploding in case it overpressurizes. To test the valve, homeowners should turn off the electricity to the hot water heater or turn the gas to pilot, then shut off the cold water inlet. When the trip lever on the valve is pulled, a rush of air, water or vapor exits through the valve if it is functioning normally. It's best to flush the tank after checking the pressure valve.