Why Damper Block-offs are Not Installed

Articles are for info only. Fireside cannot be held liable for their use or misapplication.

Written by John Debar, Owner / johndebar@gmail.com / 401-783-6054

With the invention of flex pipe, and its price decrease, the pipe now terminates at the top of the chimney, unlike the recent past where the pipe just went through the damper with a damper block-off plate.

With the full liner pipe now extending to the top, the space around the pipe is sealed at the top with a metal plate. Underneath the metal plate, insulation surrounds the uppermost few feet of pipe. Thus, there is no flow of air out of the chimney, nor any heat lost. The 6-8 cubic feet of air space remaining around the liner will warm slightly, but it is not a measurable amount of heat.

This heat does not escape outside. This tiny heat keeps the liner from getting overly cold when the stove is not in use, otherwise, the cold heavy air will resist initial flow on stove start up, and be prone to smoking out from the stove opening and into the home.

Smoking can also occur due to other factors. If there is smoking, then please refer to the smoking/start-up troubleshooting page or wood stove smoking page for simple tips to remedy.

Added Note: Air coming down the fireplace is very common- almost always the case where flue tile joints are missing in a few places, and especially in the case of a chimney fire, cracked tile chunks can come out when cleaning.

Air coming down the fireplace or any opening in the home is pulled down by attic shingle cap vents, and/or a venting dryer, and/or furnace and/or kitchen / bathroom fans, or any one of these. If these are to vent, a surge of make up air must come in the home.

If you sealed up every joint of the chimney, then the make up air would come in more-so somewhere else. If all nooks and crannies of the home are sealed up, the furnace and others could not vent at all.

John Debar - Engineer/ RI Reg # 1719
Heating Appliance License #7808 - Since 1987
Ocean State Chimney (www.OSChimney.com)
Fireside Stove Shoppe (www.FiresideOnline.com)
52 Main St, Wakefield, RI 02879
401-783-6334 / 401-249-1818 Providence / 401-847-3882 Newport