Question: My husband and I purchased a new home - and it has a pre-fab fireplace. From what I now understand it is one of those that are made basically for looks and not use. If you burn more than one piece of wood the house fills up with smoke which in turn sets off the smoke detector. Answer: Read the stuff at HearthNet (in the https://www.hearth.com/what/specific.html ) - at the bottom of the page- there is some good info about chimneys and starting a fire. <p> You may also want to try cracking a window open in the room with the fireplace. The fireplace may be starve for air, which will make it difficult to start.