When using a wood-burning fireplace, more heat can be lost up the chimney than is produced by the fire itself. To reduce heat loss when using your fireplace, follow these suggestions: 1) Lower the thermostat setting so your system doesn't keep trying to replace the warm air being drawn toward the chimney. 2) Open the window nearest the fireplace about one inch and close any doors in the room so the fireplace can't draw heated air out of the house. 3) Install glass fireplace doors to help keep the warm air in the room. 4) Close the chimney damper when the fireplace is not in use.