I think when the person who had installed my harmon three years ago and came back in siliconed everything up, messed up my cleanout T cap. He siliconed that, and then, of course, I contacted them and said what the heck that needs to not be siliconed, because I need to be able to get to it to clean out the stove. He came back and tried to get the silicone off by scraping it and cutting it. I really think he just messed it up because now smoke is leaking out of there too. I did put silicone tape around it, but I do think i'm gonna need to just replace it. Are these caps all universal depending on the diameter or do I need to know what specific pipes these are. These pipes were installed over fourteen years.ago, when I had my first pellet stove put in. Attached a picture of what my clean out looks like..