Chimney Masters Blog

A top sealing damper is a spring-loaded, gasketed lid mounted at the top of the flue and operated by a stainless cable running down to the firebox. Closed, it seals the flue against air leakage far better than a worn throat damper, cutting the stack effect that pulls conditioned air out of the house. Open, it clears the full flue opening and doubles as a rain and animal cap, which supports steady draft.