My damper is 4 feet up the chimney and has a pull chain to open it and vents in the flue wall underneath.

My damper is 4 feet up the chimney and has a pull chain to open it and vents in the flue wall underneath.

Q: Jason, I have two issues. The website indicates that the chimney pillow should go above the damper. Our damper is about 4 feet up the chimney chute. It’s attached to a chain and when open, the damper bisects the flue in an up and down position. Would we still position a pillow above the damper? How?

Also, We have a set of vents below the damper on all four sides. There are about 6 horizontal vents per side and they extend from right below the damper to about 8 inches below. Can I install over those? – SS

A: Dear SS, It sounds like you have a Heatelator brand fireplace. I have done many installs like this one you described. As a matter of fact, there was a condo association in IL that had hundreds of these Heatelator fireplaces with butterfly dampers and vents underneath just as you described. See attached picture.

You will find a small ledge just above the firebrick lining the firebox. That ledge is a perfect spot to install a 36×15 Chimney Balloon. That area is trapezoid in shape but the 36×15 will have enough material to plug it anyway. See attached picture of Chimney Balloon installed. – Jason

My fireplace firebox area is a trapezoid shape. Does a rectangular Chimney Balloon fit a trapezoid shape?

My fireplace firebox area is a trapezoid shape. Does a rectangular Chimney Balloon fit a trapezoid shape?

Q: Hi Jason, my fireplace is a sort of rectangular shape (more like a trapezoid) measuring 26 x 14. It goes straight up at those dimensions, then changes to slanted pieces of sheet metal up to the damper that is a circular opening 8″ in diameter. I’ve attached my attempt at a drawing. I’m not really sure what size Chimney Balloon I need. Can you advise, please? – CC

A: Dear CC, The diagram helps quite a bit. Thank you for sending that. In this particular case, I would install the Chimney Balloon just above the damper. A 9×9 Chimney Balloon with an HEK extender attached will give you the length of handle you will need to get it installed in the proper place. I would assume from your circular flue that you have either a butterfly damper (one that picots in the middle) or a drop-down damper (hinged on one side and it drops down like a trap door). The 9×9 and HEK combination will work well with either configuration. – Jason

How to plug a round 8″ flue pipe with a swivel damper?

How to plug a round 8″ flue pipe with a swivel damper?

Q: Hi Jason, Here are a few pictures of my fireplace damper and round flue pipe. The diameter is 8″ in the flue pipe. What size Chimney Balloon do you suggest? – LG

A: Hi LG, This application is one of the most common styles of damper and flue that we run into. These pre-fabricated fireplaces are very common, but the butterfly damper that you have there is notoriously leaky. The great news is yours looks like it has never been used, so you will have no soot to deal with when you install a 9×9 Chimney Balloon. Take the deflated Chimney balloon and slide it in past the open damper. Put a couple of puffs of air into it and make sure it is installing nice and horizontal. Then inflate it the rest of the way until it tightens up, and close the valve. The 9×9 install is very easy to do. – Jason

#2: I Have a Circular Center Pivot Damper with No Handle. How Do I Plug the Round Flue Pipe?

#2: I Have a Circular Center Pivot Damper with No Handle. How Do I Plug the Round Flue Pipe?

#2: I Have a Circular Center Pivot Damper with No Handle. How Do I Plug the Round Flue Pipe?

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 to install a Round Flueblocker below the damper door (image 2-5). Or you can install the round Flueblocker above the damper (image 2-4).

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 someone fires up the gas logs without asking, they won’t back up exhaust fumes into the house. The Chimney Balloon will burst and fall out, since it is designed to sacrifice itself if introduced to flame. 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 or disable 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 fumes will back up into the house. So DO NOT light a fire under it.