I noticed last year that there is a small gap that I cannot adjust the door enough to remedy. I have not noticed any smoke escape to this point but I thought before this heating season perhaps I should do something before the gap and inherent air leak becomes a problem. Mfr sent me a rope gasket...although they were to have me what they called a "kit"...so after a couple of pone calls I received the "kit" which is 2 parts...a small tube of Gunk RTV gasket maker and a gasket that appears to be some sort of heavy rubber. I had planned on taking out the old gasket and installing the new rubber type one and of course sealed with RTV but then I thought that since the gap I have is not very long or deep could I not just apply another layer of RTV to the existing one to build it up a bit and hopefully have full contact between door and boiler?