Can a blockout plate be bad thing?

[Cedrusdeodara]

My installer warned me about putting in a blockout plate because he said my 6" Stainless steel sleeve isn't insulated and that I need the heat from the firebox to keep my sleeve warm. Could this be true?

I just swept the sleeve this week and recovered nearly a full 1-gallon bucket of creosote/soot after burning for only two months. Sound like I need insulation around that sleeve huh (or the installer didn't insulate well under the cap and air might be getting in between the flue and the sleeve from the outside)???

 

[begreen]

The combo of a cold exterior chimney and semi-dry wood can generate a lot of creosote quickly. Is this an exterior chimney? How well seasoned is the wood?

 

[Cedrusdeodara]

Partially interior (first floor) and exterior at the second story up. The wood is fairly well seasoned. I cut mainly standing dead trees and I sort the wood as "seasoned" and "not seasoned" when stacking (get a wide range of wood when cutting standing dead, from greed wood to well seasoned trees that have been dead a couple of years). Probably not the best wood in the world, but I definitely try and burn only the lightest and most seasoned pieces.

Brian

 

[Cedrusdeodara]

Something else just dawned on my, my chimney has two flues, the second one is no longer in use and is capped off in the house, but still open at the top. I guess that could be cooling the inserts flu, as they are adjacent to eachother in the chimney???

 

[international5288]

He's right, I am going through this right now. I recently installed a blockoff plate to help keep heat from going up the chimney. (exterior chimney, uninsulated 6" liner) It made a big difference in the amount of heat going into the room, but an unanticipated consequence is that it reduced my draft a good bit. I have an insulation kit ordered and will be installing it in the next couple days. It is going to stink having to pull the liner out and wrap it, but live and learn I guess.

 

[begreen]

Agreed, insulate the liner and you will maintain a hotter, safer flue. Once you are burning only wood that is 20% moisture or less with the insulated liner, a blockoff plate should help the insert deliver more heat to the house without serious creosote accumulation.

 

[JimmyMood]

He's right, I am going through this right now. I recently installed a blockoff plate to help keep heat from going up the chimney. (exterior chimney, uninsulated 6" liner) It made a big difference in the amount of heat going into the room, but an unanticipated consequence is that it reduced my draft a good bit. I have an insulation kit ordered and will be installing it in the next couple days. It is going to stink having to pull the liner out and wrap it, but live and learn I guess.

Good point about the draft, I was wondering about this myself.

You can pour vermiculite down between the liner and flue. Since you already have the block of plate on the bottom, I would think that you would be all set.

http://www.chimneylinerinc.com/insulation_kits.htm

 

[stejus]

My insert is scheduled to go in Dec 26. The sweep installer said an insulated liner will not work in my flue because it's just too tight with a 6" liner. So for now he said just a liner and he'll come back in the Spring to install a blockoff plate and pour in the insulation and water mix. Thirteen more days before the first breakin fire!

 

[RedRanger]

Glad I don`t have the lower blockoff plate in our "evil exterior chimney".. As it is now, by the time 9 pm rolls around it is usually about 86F in the rec-room. And that is only the first reason.

Second reason in our case is I need some heat going up the 5 inch SS Liner to totally minimize any cresote buildup.

Just saying--I`m totally happy with the heat output. Matter of fact, any greater heat output would be an inferno!!