I have a question concerning the Harman P38 OAK. The kit recommended by Harman for the P38 includes a 2 3/8" ID flex pipe to run from the stove to the outside. The inlet on the stove is at least 3" in dia.. This requires the pipe to be merely 'stuffed' into the opening. Is this really correct? Has anyone actually placed a flex pipe with a diameter that actually fits over the inlet? I have used the recommended setup for several years but it just does not seem correct.