I have chimney flue that is slightly reduced by modifications done by a previous owner.as I would like to have installed a new gas fire and I can not find one to work with our flue size. so I am considering a balanced flue gas fire. this would seal off the fireplace opening. this is fine but I would then need to ventilate the chimney. I am wondering if I could use an air brick on the outside wall(the chimney is on outside wall) to create an airflow in the chimney and remove the need for vent from the room. any help would be much appreciated.
