Hi there I have just moved into a house where the heating is a Kent Tile Fire it looks similar to the pics of teb ones from the 1980’s. I have no idea how to use it. It only has one lever on the top left hand side that seems to lock the door. Is this also the air? Not sure if there is a damper? Any help would be very much appreciated. It’s going to get cold here soon! will post a pic if I can. Work out how