Here is my situation. I have smoke on start up on my ahley 5500xl made by USSC. I've shortened the vent some just to see if that would help. That did help some but I still have smoke. I have new pipe new stove. The piping is as follows (basement installation) 1 T, 5' of pipe, 1 90 elbow, 2' straight, 1 T, 1' pipe, 1 90 elbow, and a cap, all 3". I know my pipe is a bit under sized which I found out after I already got the pipe dirty by running the stove outside. I have a nice brown film on my glass. All of the pipe joints are sealed with RTV. The smoke is coming out around the appliance adapter I think I'm just not sure. I've tried using a flash light in the dark. I've put more RTV on the outside of appliance adapter. The next step would be to take off apliance adapter. Have I missed anything? Does anyone have any help to offer?