Hi, this whisky4 asking about what is the highest/and/or safest tempature that a chimeny in a 1924 house can handle,has no dampener,and was checked by chiminey sweep and was OK the back of the box has a slope to it,but I noticed that the bricks at the back appear to be worn off by the years of fires in fireplace it also appears that bricks are fairly thick as the fire box area goes outside of the house about 18 inches,also if I put a pellet stove in fireplace do I need to put a liner in flue,thank,s whisky4