Last fall, I got a leak from the nylon plug, it broke when I tried to tighten it. So to get it out, I marked some of the threads. Now with the new plug in, and I also used teflon tape, i get a leak when the water heats up. It's ok when it's cold. How do I stop the leak? Would plumber's dope be better than teflon? or plumber's putty? or both?
As a plumber , I have found that most people don't use enough teflon tape. For a 3/4" thread, you should tightly wrap enough tape to make the threads appear "Rounded" (about 8-10 wraps). Pipe dope will also work and will not only seal but make it easier to remove as it is a lube also.