I have an Englander 25pdvc that was installed by a friend that was my first mistake. When he installed it I was a total newby and figured he knew what he was doing after reading this forum I now know better. So anyway my Ps is in the center of my living room using the fireplace for venting. Its been installed 2 years. The convection fan has always been noisy but has gotten louder and didn't seem to blow as much as it used to. I decided to take it apart for a cleaning and maybe a replacement. Lets just say we are lucky to be alive now I want to redo the whole thing right. Its to cold to get on the roof so I just want to make it safer to get through the winter. I'm going to seal the pipe joints with high temp silicon 1st question can I use make a gasket? I also need to install a temp oak(I leave a window open) if I can. 2nd question can I buy a piece of 2 inch pipe and run it part way up the chimney but below the top of the exhaust pipe will that be ok or will it suck in smoke? Like I said this summer I'm going to redo the whole thing with flex pipe a cap and an oak. I just need to get through the winter and anything has to be an improvement from what Ive learned from this forum.