How to remove double wall chimney pipe

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

JHolden

New Member
Jun 19, 2018
22
Maine
Hi all, our stove pipe runs single wall downstairs, then switches to double wall in the bedroom. I believe the double wall section in the bedroom has a leak. I can see creosote stains on a joint. How do I remove the stove pipe sections so that I can take a look. Do I just pull the locking rings up and separate the sections?
 
The pipe in the bedroom is chimney pipe. Is it possible that the creosote stain is from above and just dripped down lower? Also, if the label is still on the pipe, make sure it was not installed upside down. Pictures will help us see what you are seeing.
 
Ill take some pictures when I get home, but the stain is on a joint between two chimney sections. the end of last season that bedroom smelt strongly of wood smoke.

I also noticed a creosote stain in the snow at the base of the chimney.
 
Attached is a picture, hope it helps
 

Attachments

  • 55112170423__F3851ACB-B0FE-4F28-ACB7-5B81C632B9A2.JPG
    55112170423__F3851ACB-B0FE-4F28-ACB7-5B81C632B9A2.JPG
    65.6 KB · Views: 1,683
can't answer question about taking that pipe apart, but with creosote running down that way either you have green wood ( not dry enough) or are burning at way too low a rate -hence the flue is not staying hot enough to keep the creosote vaporized. Green wood will cause this. I do not know any retailer that truly sells firewood that is at 20 or less % moisture contact- a lot are advertising kiln dried when in truth it is more like just enough to kill bugs which is x amount of hours at x temperature. 4 or 5 hours is not generally enough to dry splits to less than 20% internally.
 
Usually the locking band is removed, then the pipe is rotated to screw it off. Do you know what brand chimney pipe this is? Are there any labels on the pipe?

FYI, chimney pipe is supposed to be enclosed in a chase as it passes through a room.
 
No idea on the brand. It is possible that the wood was green, we cut and split our own firewood. would green would explain the smell of wood smoke?
 
Green wood would explain the excess creosote, but it would have to be quite serious to leak out of a chimney seam.

Have the chimney inspected by a professional for proper installation and creosote accumulation.
 
Possibly- that creosote will also act as a bit of glue. It would also give off a wood smoke smell particularly in the warm humid months. When it is warm and running/ dripping like that pic shows then also.
If you are cutting / splitting now for this winter that would be the main culprit- green wood. Most wood is going to take 2 years or more to dry out after it is split - the reason for the 3 year plan- split this year for use 3 years later and then a constant rotation.
 
The pipe is a Hart and Cooley. I lit off a pizza box and watched for smoke. The pipe is leaking smoke on a joint.

I lifted the rings top and bottom and tried to screw the sections apart (as someone suggested) but the are not separating.

As the pipe warms up the joints are warmer than the middle of the pipe
 

Attachments

  • 21DD2616-36EF-4531-B017-D84904F723D6.jpeg
    21DD2616-36EF-4531-B017-D84904F723D6.jpeg
    79.5 KB · Views: 1,159
  • 725923FD-A9A5-4BD6-9C33-66418F329230.jpeg
    725923FD-A9A5-4BD6-9C33-66418F329230.jpeg
    68.2 KB · Views: 3,009
Last edited by a moderator:
Im just spitballing here but I think the inner liner may be rusted away at the inner pipe overlap joint. That pretty much gives a straight shot to the outside between the joint. That by itself wont make it leak smoke because a drafting chimney sucks in at leaks. Im betting there is a major blockage on up the pipe as well. When was the last time it was swept? How old is the pipe? Looks pretty old judging by the locking tabs.
 
  • Like
Reactions: begreen
The house was built in 1999 so I can only assume it’s of that vintage.

I am pretty sure that there is no blockage, I sweeep it myself at least Quarterly.
 
By the looks of that and your description i would bet your chimney is shot. There should be no way at all for that to happen if the chimney is installed.correctly and in useable condition
 
Ok can someone give me instructions on how to dismantle this section?
There are plenty of times we need to use a grinder or sawzall. Creosote is an excellent glue. I beleive that pipe should just pull apart after the band is pushed up. But it is probably glued fast
 
I just did another smoke test. It is no longer leaking out of the joint. Maybe the twisting and lifting in an attempt to separate it may have sealed it??
 
Ok completion of third smoke test, (no more junk mail) all joints are leaking in the upstairs. All individual sections upstairs move I just can’t figure out how to separate them?

Do I need to go up on the roof and pull the pipe out that way?
 
Ok completion of third smoke test, (no more junk mail) all joints are leaking in the upstairs. All individual sections upstairs move I just can’t figure out how to separate them?

Do I need to go up on the roof and pull the pipe out that way?
Yes you would want to start at the top. But if the joints are leaking smoke there is something very wrong. Even if the chimney is completly blocked there should be no smoke escaping the joints in the chimney.
 
The individual lengths will be trapped. You have to unstack it from top down unless it is hung from the roof deck as in a cathedral application.
 
The individual lengths will be trapped. You have to unstack it from top down unless it is hung from the roof deck as in a cathedral application.
Hard to say without eyes on site. Could be the pipe is corroded, mis-installed, fully gunked up, etc.. I wouldn't burn until the chimney has been thoroughly inspected or replaced.
 
Ok so an update, I CCTV’d the inside of the stove pipe. I taped my phone to my brush set and slowly went up and down the chimney.

The video didn’t show any issues. HOWEVER, I think I have a blockage in the rain cap. Would that be the source of my problems?
 
Ok so an update, I CCTV’d the inside of the stove pipe. I taped my phone to my brush set and slowly went up and down the chimney.

The video didn’t show any issues. HOWEVER, I think I have a blockage in the rain cap. Would that be the source of my problems?
A blocked cap screen is common when burning green wood. Even with a blocked cap though the chimney pipe joints shouldn't ooze or leak smoke.