05-09-2018, 02:43 PM
Your picture shows an arrow to the System Pressure relief valve.... It's set to open automatically if the pressure in the tank/system goes to high.... Not sure what it is set to but that is NOT the way to drain the tank for winterization..... The valve you are looking for is also shown (slightly) below brass pipe coming out of the heater on the left in your picture.. It's normally a gray plasic valve....
