At the end of the season I was starting to get smoke leaking out of the exhaust pipes behind the stove. The leak looks like it is comming out of the cleanout at the base of a T. It looks like the smoke is comming out the bottom, and not at a joint. I am thinking that the cleanout needs to be replaced. The problem is that I can't get it off. I think the installer used sealant on the joint. Is there a trick to getting the sealant to release other than brute force. It is a twist connection. If I cant get it off, should I fill the groove on the bottom with high temp sealant?