have a certified chimney contractor (we have such specialists in Pa), they can repair clean out and relin your chimnyeys to actually pute em back into use and keep annimals like bats from living in your house. e have a house that was a small hotel and a post office addition. It was first built as a stone cabin in 1763. It was added onto in Federalist and other styles since then. Its had maybe 7 additions over time. It had fireplaces and Franklin toves in all rooms. eve had all except 3 xhimneys taken out and the remainders were fixed religned with asbestos cement and Stainless steel liners (We have one chimney that serves two fireplaces and our gs heating system. The other chimneys have a wood stove and one huge fireplace with a cooking crane.
The work doesnt come cheap but, aas one who had a chimney fire after the relining, the firemen coulnt even detect any thermal ignature into the house (All the chimneys are within the walls)
We use one of the fireplces for actual heat. e keep it pretty much burning from Novemeber through March,
We love the heat and the mild smell it imparts to the room.