After a month of frustration trying to control the stove temps on my new EPA stove, I finally installed a pipe damper in the ovalized stove pipe. Today was my fist test, and what a difference! It turned an uncontrollable bast furnace into a nice friendly stove. Life is good again. Custom fitting a damper into double walled oval pipe was a challenge, but she's a done. I found that 32+ feet of 8" pipe in a center chimney colonial created a draft what would suck the hair piece off your head! I had previously tried replacing all the gaskets, blocking off part of the secondaries but nothing worked, and the stove could not be controlled. Hopefully the temps outside will drop bellow 50 again so I can see what she can do.