I went to drain my water heater last night (nice TOH video showed me what I needed to do!), and found that the drain valve didn't have a cap that I can turn. Believe it or not, I can't find one. I have a pretty standard State ES652DORT water heater. Any suggestions on how to find a new cap or how to get the thing to turn without one, would be much appreciated, as I'd like to flush the water heater before a big freeze.