Chimney Damper Repair in Connecticut

The damper is a plate that sits in the throat above the firebox and opens or closes the flue. Open, it lets smoke out while the fire is burning. Closed, it stops heated air from the house disappearing up the chimney when it is not.

It has to do three things: open fully, close fully, and seat when it is closed. A damper failing any of the three produces a recognisable complaint. One that will not open fully restricts the draft and pushes smoke into the room. One that will not close, or does not seat, lets conditioned air out of the house all year — a quiet and continuous cost.

Traditional throat dampers are cast iron in a masonry throat, and they fail through corrosion, distortion from heat, or simply being caked with deposits. Top-sealing dampers sit at the top of the flue instead, close with a gasket and are operated by a cable from the firebox; they seal considerably better.

A damper caked with creosote and soot is often simply cleaned and freed up, which is the best outcome and frequently what the problem turns out to be. That is part of a chimney cleaning rather than a separate job.

Where the plate, frame or mechanism has corroded or distorted, the choice is between repairing the existing throat damper and fitting a top-sealing damper at the flue opening instead. Top-sealing dampers seal better than a cast iron plate in a masonry throat ever did, and they keep rain out of the flue as well, which is why they are often the better answer on an old fireplace.

Replacing a throat damper in place is possible but is masonry work — the frame is built into the throat. That is worth knowing before the decision, because it changes the scope considerably.