Fireplace draft

[Sunday4]

I have a wood burning fireplace that I have probably used once in the past couple of years. Even with the flue and glass door closed, there is a draft. I think I'm losing quite a bit of heat through the fireplace.

I don't plan on using this fireplace as a wood-burning fireplace anymore... Maybe the next owner will want to. I want to insulate the flue somehow so there is no draft and install an electric fireplace insert. This must be done in such a way that I can remove the electric insert when I want to and use it as a wood burning fp.

Any suggestions?

[John_B]

Take a fistful of fiberglass and stick it into the flue.

Remember to remove it before you sell the house.

Sunday4 wrote:

[AJScott]

I had exactly this same problem with the steel wood-burning fireplace installed by the idiot who owned my house previously. The damn thing leaked cold air draft thru the box like nobody's business even when the flue was shut. When we demo'ed our basement and ripped down the false wall fronting the fireplace, it turned out that they did a significantly piss-poor job of mortaring the spot where the galvanized-steel chimney ducting went thru the brick wall. The job was so piss-poor that you could see daylight where the two met. Might be that you have a similar problem.

That was the least of the installation injustices, but that's another story for another day.

AJS

[Terry]

Is one supposed to use 'galvanized' steel flue piping? Could not the galvanizing vapourize, under certain conditions of heat and posibly be poisonous? Just a question. BTW that's what we have done, stuff a bag filled with something like f.glass insulation or even crushed up newspaper up the 6 inch by 8 inch flue; but remember to remove it if/when you want to light a fire! We hung a piece of red tape on the fire screen as a reminder. I'm working on something better than that but trying to avoid elaborate chimney top devices with springs that could corrode etc. Windy here too! Such a device was shown on 'This Old House' costing about $160 US installed; a bit costly for my taste. Maybe something chain operated down the flue pipe? Our flue is just about straight. Terry.

[Mark Cato]

The most effective way to seal the flue (and still have it work when you want it to) is with a top-mounted damper. They achieve a much tighter seal than the conventional throat dampers, and are easier to operate. It may be a more expensive solution than your considering, but worth it in the long run considering the impact on your heating bill.

As far as brand, I prefer RMR. The springs are located under the cap, but above the damper plate. The springs won't freeze shut or be subjected to the byproducts of burning. To open the damper you release the cable at the bottom. I recently installed one at my parent's house, with a very noticeable effect. (By the by, I'm not affiliated with RMR.)

If you want the el-cheapo semi-permanent solution, cut a metal block-off to size and silicone it to the top of the flue. No more draft. That's what I've done temporarily to some of my non-functioning fireplaces.

HTH,

mark

[Mark Cato]

Sorry to follow up my own post. I wanted to add that extreme care has to be used when blocking off flues from the top. You want to be absolutely certain that the flue you are blocking is no longer venting, and that you're blocking off the proper flue. Accidentally sealing your working furnace flue, etc. rather than a non-functioning fireplace could have serious, life-threatening consequences.

mark