I have an old Timberline wood stove & the chimney is over 30 feet high. The stove started having smoking issues so I had it cleaned (there was lots of creosote!) and they discovered cracked tiles in the chimney. They are going to install a stainless steel liner, but we have encountered many problems. The opening on the back of the stove is 8" and they where planning on installling an 8" oval liner (flue is oval). The liner cracked during the process (it is not as flexible as a round liner and they did not have the proper equipment to handle the job). It also caught on something protruding inside the chimney about 5 feet above the thimble area. They gave me two options. Cut an opening in the back of the chimney, clear the obstruction and pull a new 8" oval liner down the chimney or attach a cone with a rope on a 7" round & pull it down - no need to cut an opening in the back of the chimney. They assured me the chimney is so tall that going down 1" in diameter would not cause draft problems. Well, the 7" caught in the same place. Now they are telling me that they will have to cut the hole to install the 7" round. They suggested a 6" round might work without cutting a hole, but I think that is too small. My question is do you think a 7" round will work okay with an old Timberline 8" since the chimney is very tall? They said it should be fine. To install the 8" oval, they would need a bucket truck to hold up one end while the other one is pushed down inside the chimney. Otherwise it will bend too much and crack. The 7" would definitely be easier to install although both require cutting an opening in the back wall. This is my first wood stove. Will a 7" liner work okay with that stove? Also, if I bought a more efficient stove in the future, would I be able to find one that works with a 7" liner or is that an odd size? Any information would be greatly appreciated. Thanks!