Here is my situation, when we brought our house,it had a wood stove in it, it was junk and I removed and trashed it, I just caped the hole, chimney is in great shape. I just got a pellet stove and wanted to hook it up where the wood stove was, when I went to get the adapter for the 6in down to 3in stockpile, I was told it won't work, that I need to put a 3in liner all the way up. Is this correct?