I'm not exactly sure what type of heater this was (I think Pentair natural gas), but I could not get this drain plug out for the life of me. It's a metal bolt. I soaked it with PB blast to try to loosen it but it only continued to strip. I blew the water out of the heater with a Cyclone. I also filled up the heater with antifreeze. Do you think I am safe leaving this plug in? I really don't know what other options I have but to try to drill and extract but don't want to if not necessary. See photo. Thanks!

