I just got my boiler chimney lined with SS 6" liner as my chimney was never completely lined and was built in 1919. The only lining is the seperation b/t the boier and fp which seems to be very weathered terracotta. All of the other walls are the original brick. Everyone that has looked at it said do not use the fireplace which makes sense. The chimney guy who did the boiler liner gave me an estimate to reline the fireplace side as well but I have yet to get this done. My question is whether it will vent succesfully or if he is just trying ot get me to spend $ for something that won't work anyway.
He recommends a 6x10 rectangular SS liner. My chimney from firebox to top is about 25 ft. The width at the widest point of the firebox is 30 inches but it is only 19-20 inches deep. I read somewhere that with a rectangular liner you needed a 10:1 ratio of firebox area to liner area. But I just read some comments that the height of the chimney was a factor as well. Any advice would be much appreciated.