Fireplace #2: Butterfly Damper with External Handle

The good news about this application is there is no damper hardware to fight with around the damper door. The damper handle is usually on the outside lintel face of the fireplace. Sometimes those handles don’t even work, because they get disconnected or rot out. But that doesn’t matter, because we don’t need them anyway!

Wood Burning Fireplace Users: Believe it or not, this application makes you very lucky. You will notice that there is a small 1”or 2” vertical bit of chimney pipe sticking down below the closed damper before the pipe opens to the firebox. This is the perfect spot for a Round Flueblocker.

Just make a diameter measurement of the hole below the damper (image 2-3), then buy a Flueblocker that will fit in that hole. Or buy one that is a bit big for the hole, since you can then trim it down to fit with a sharp pair of scissors. Here are some examples:
Example 1:  You measure 8” diameter = You buy a 9” Round Flueblocker
Example 2: You measure 9” diameter = You buy a 9” Round Flueblocker
Example 3: You measure a 11” diameter = You buy a 12” Round Flueblocker.

Note: Flueblockers are physically a little bit larger than their labeled size. This is so they can press in to fit and hold in place by pressure tension.

Gas Log Users: If you have a gas log in this fireplace, you have a decision to make. Here are your two options:

Option 1) You can turn off the gas line to this fireplace and put in a small 9×9 or 12×12 Chimney Balloon just above the damper. This way if your idiot cousin comes over at Christmas and fires up the gas logs without asking, he won’t back up exhaust fumes into the house. The Chimney Balloon will burst and fall out since it is designed to do that. The downside to this, is the Chimney Balloon is an inflatable and not as durable as a Flueblocker so it will wear out after time. Also, you will have to install the Chimney Balloon above the open damper.

Option 2) You can turn off the gas line and remove the gas log set and then put in a Flueblocker. The Flueblocker does not burn off if you light a fire under it. If you do light a fire under a Flueblocker bad things happen…enough said.

Gas logs are a separate conversation. We have another article on how vented and ventless gas logs can poison you or pick your pocket over time