Cold air leaking from double wall stove pipe joints

[sheneron]

I just installed a double wall stove pipe and where there are small gaps at the joints I can feel cold air leaking (quite strongly) on my fingers. Do I need to somehow seal these joints or is there a way to prevent cold air from coming down this stove pipe.

I have an unfinished attic above this space, which is the origin of the cold air, still surprised how much is coming through out of this pipe...

 

[xman23]

The pipe connections are not sealed. When the stove runs the draft pulls air into the pipe. With this condition you may have a draft startup issue. More important how is it burning?

 

[sheneron]

Well, I haven't burned yet since I put in those new pipe. I suspect it will be fine when burning, but I'm concerned about the majority of time when it's not burning but pulling cold air in.

However, I did notice my stove damper was fully open, and I put it to most closed setting and the air leaking through the pipe cracked feels pretty minimal now. Hopefully that will do it, I'll keep checking it tonight.

 

[Trevor Tahclep]

That does not look right, what make and model of stove pipe is it ?
Who installed it ?
Was it installed correctly as per manufactures requirements ?

 

[Eman85]

That's the 2 outer parts of the DW pipe where they overlap. The little air can't be coming from your attic, would have to be from inside the chimney. Odd that cold air would be somehow coming down the pipe unless it was windy. If the pipes fit together good and you have the male ends pointing towards the stove there shouldn't be a problem.

 

[sheneron]

Yes this is the outer part of the DVL double wall stove pipe. Cold air does (still) leak out of the seams, both in the spot pictured above and the seam of the telescoping piece.

The air is the same temperature as would be in the unfinished attic above this pipe, but I'm not sure why it would be leaking out here in the outer section of the double wall.

I have started a fire a few times and no smoke or anything comes out of the pipe. I did find that the fire doesn't draft up immediately when I start it unless I really get it going fast and hot.

I definitely welcome any ideas or feedback. I did this install myself, but I was just replacing the previous stove pipe that was an incorrect material.

 

[sheneron]

For what it's worth, if there is no fire and I open the stove door, I can feel cold air coming down into the stove.

 

[Trevor Tahclep]

For what it's worth, if there is no fire and I open the stove door, I can feel cold air coming down into the stove.

Are you certain it is not a negative pressure scenario, I get those a few times per year, sometimes a few days in a row and other times only one or two days. My solution is a strong fire with lot's of small kindling and very small splits with 5-6 extra sheets of newspaper on the top to heat up the air to the chimney very quickly, once that happens it reverses the downdraft and the chimney updraft starts back up.

 

[sheneron]

Are you certain it is not a negative pressure scenario, I get those a few times per year, sometimes a few days in a row and other times only one or two days. My solution is a strong fire with lot's of small kindling and very small splits with 5-6 extra sheets of newspaper on the top to heat up the air to the chimney very quickly, once that happens it reverses the downdraft and the chimney updraft starts back up.

Yes, I think it is negative pressure. Sometimes, I feel the cold air leaking and sometimes I do not. To be clear, I have no issues with smoke, or starting a fire, it's only when there is no fire, that there appears to be negative pressure. Perhaps it's a house issue? Anything I can do?

Are you saying that when you heat up your fire it fixes the negative pressure situation even after the fire is out?

 

[Trevor Tahclep]

Yes, I think it is negative pressure. Sometimes, I feel the cold air leaking and sometimes I do not. To be clear, I have no issues with smoke, or starting a fire, it's only when there is no fire, that there appears to be negative pressure. Perhaps it's a house issue? Anything I can do?

Are you saying that when you heat up your fire it fixes the negative pressure situation even after the fire is out?

NO, a hot start up will fix it for that day or as long as their is a fire and sufficient heat in the stove. We burn 24/7 here once the really cold weather begins ( mid December to mid April ), no negative pressure scenarios then. During shoulder season fall and spring is when I get negative pressure because we let the fire die out in the evening. Some people use a propane torch to push the cold air up and out when starting their fire in the morning.

 

[BillBurns]

I use a small space heater with a blower, pointed into the stove, damper opened....5 mins Im good to light her up.

 

[sheneron]

Thing is, I am not really worried about starting fires; In fact, I don't have much issue with the negative pressure when starting a fire, it reverses very quickly. What I am worried about is losing heat in the house when I don't have a fire going. I don't run my stove all the time, more like a weekend or every other weekend user.

So, I don't like the thought of having something constantly leaking cold air into the house, other than when it's occasionally used every other weekend.

 

[BillBurns]

I sealed my iside joints with a High Temp. Sealant. Seems to work, been 3 years........

 

[Trevor Tahclep]

If you can find a piece or two of cut off ceramic fiber blanket from a stove dealer or installer, stuff some up in there with a small blade or screwdriver then add a screw or a pipe collar band of some kind. Perhaps a few strands of unwound door gasket would do as well.

6" ID Single Wall Black Stove Drawband

This 6" black draw band primary use is to connect 2 6" pipe sections together. This product has a maximum operating temperature range of up to 800 degrees Fahrenheit due to a special high heat coating that is directly applied to the cold rolled steel substrate. The straps are zinc plated steel.

www.menards.com

 

[Eman85]

I'm still lost at the cold air at the edge of a DW pipe. The outer skin of the DW pipe should have no way of having airflow from outside or the attic. The cold air coming into the stove shouldn't be a problem if the stove is closed when not burning.