We live in a 1650s building in bradford on Avon, England. We have recently had the chimney rebuilt and the draft was really good, but the condition of the chimney was a bit suspect, not having been lit for nearly 100 years. After installation of a liner, the room fills with smoke. There still appears to be a good draft, but the smoke still comes into the room. We want a wood fire for Christmas! Any suggestions gratefully received.