[1990C4S]

I have a existing fireplace with (I think) a clay liner. It is about 50 years old. I have a number of issues that make me think the fireplace should be lined.

I do not want to get a wood burning fireplace insert, I want to keep the original fireplace. Looking online all the diagrams show an insert made to connect to the 6" stainless liner.

Has anyone done this upgrade with the stainless liner? It sounds like I may need to remove the clay liner and install an insulated liner. And I would like to go with an external damper, at the top of the chimney, that makes more sense to me.

How is the liner terminated where the damper is now?

Does it have to be an insulated liner for a wood burning fireplace if I go through the existing chimney? i.e. Can I just slide a 6" liner down the clay chimney?

I also have a second flue that used to be (I assume) for the oil burning furnace. That should be capped with cement, should it not?