The Thermes is our high-efficiency balanced flue gas appliance. If you have no flue or chimney in your home you will need a balanced flue gas fire. The Wildfire Thermes Gas Fire is a room-sealed high efficiency gas fire that really delivers. This fire flues through an external wall and can be installed in most new or existing fireplaces. Remember, once you have chosen your appliance, you can decide how it looks by selecting a trim and fret options.