Q: Jason, I have a top style damper with a wire that comes down into the fireplace to pull tight. When I install a chimney pillow, should I open the top damper? I know doing this will allow the pillow to seal better at the location where the wire comes down, but I don't know if it is ok to leave the top damper open. I have a terrible smell that I am trying to seal off and hope the pillow will help solve this. Also, I have an ash pit opeing on the bottom of the fireplace - should I seal this with a pillow as well? - MF
Q: Hi MF,
Your application is exactly like an application I walked through for a customer in Rockford, IL and we got it resolved quite easily. I attached some pictures of the Rockford install for your reference.
The trouble you are running into is the top damper is bottling up the chimney at the top, so when the cold air conducts through the chimney bricks the cooler creosote-laced air in the chimney has no place to go but come down into the house. Often the negative pressure in the house that the HVAC introduces, coupled with the open portal between floors through the ash cleanout, will amplify the smell problem.
So here is how we fix it…. Install a Chimney Balloon just above your old low metal damper frame (top left photo). For now, install it with the chimney top damper open so the cable is slack. This will allow your chimney to vent the smell out the top, but not let the smell in the house. For the ash cleanout, take the cover off the chute for the cleanout and measure the hole going down (bottom left photo). Most of the time it will be smaller than a 9x9, so you can just install a 9x9 upside down into that chute. This effectively stops the air exchange through the chimney and the ash cleanout. After a few months you can close the top damper after it has time to air out.
One side note though. Make sure your chimney top has a built in screen over it to keep squirrels and birds out? - Jason