Condensation Nightmare

[GaryS]

I found this site while searching for an answer to my problem. I read some good information in the Q&A;section also.

background: Pacific Energy steel stove 10 years old. Flue is a steel boiler pipe in concrete block and brick outside the house. stove sits on a brick hearth in the basement below ground level. The stove pipe goes through the foundation wall into the steel pipe (which is below ground). The clean out is on the insde of the house just below where the stove pipe goes through the wall. I would much prefer the clean out door be outside but the stove is below ground level.

The boiler pipe was recommended by someone when I was building the house and it may have been a big mistake.

The problem I'm having is condensation coming down the flue and running out the clean out door staining all my brick black. It doesn't happen if the stove is always hot. If I let the flue cool off and start a new fire, I'm likely to get black water running out the clean out. The flue pipe is larger than the piple coming out of the stove so that may be my biggest problem.

When the weather is just right, not too warm, not too cold, I get downdrafts. I guess it boils down to a cold flue that holds moisture. Usually, getting a good draft isn't a problem.

I also have a rain cap on the flue so I get black gunk running down the side of the brick flue outside. This also indicates to me that the flue doesn't stay warm enough.

Where's the best place to start? Lining the flue with smaller stainless steel?

 

[begreen]

If you could get an insulated liner in there it should help a lot. What's the diameter of the boiler pipe?

Maybe another alternative would be to wrap the chimney with an insulated chase?

 

[struggle]

This is a result of cold air leaking into the chimney pipe so I am guessing there are holes or cracks in the pipe causing this. I had the exact same problem but with a clay tile lined chimney. It would literally drain black water/creosote out if the fire was not hot enough.

You face having a chimney fire if this continues!! Why do I know this because I had one after experiencing what you have.

I relined my chimney with a flex liner and it solved all the chimney problems I had. My chimney is exterior as well.

 

[fossil]

The condensation you're talking about is forming inside the masonry flue, between the interior of the masonry and the exterior of the pipe, not inside the actual pipe, is that correct? Am I picturing this accurately? Rick

 

[GaryS]

This is a result of cold air leaking into the chimney pipe so I am guessing there are holes or cracks in the pipe causing this. I had the exact same problem but with a clay tile lined chimney. It would literally drain black water/creosote out if the fire was not hot enough.

You face having a chimney fire if this continues!! Why do I know this because I had one after experiencing what you have.

I relined my chimney with a flex liner and it solved all the chimney problems I had. My chimney is exterior as well.

The flue is solid from top to bottom. The pipes are 3/8" steel welded together which raises other issues (expansion). The pipe is 1"-2" larger in diameter than the stove pipe. The exact measurements escape me right now. It's tempting to just tear it off but I will try a liner first.

Is there a good place to order it from? The place I bought the stove from hasn't been much help and they are very pricey.

 

[struggle]

Is there anyway you can post a picture of this set up?

 

[GaryS]

Pictures would be a good idea.

 

[begreen]

If the pipe is 2" larger an insulated liner should be possible. Stick a tape on the pipe and get the pipe's inside diameter.

 

[jtp10181]

Definitely if you have an 8" pipe, use a 6" insulated liner to re-line it. You will get it the right size and also convert it over to using the proper components

 

[bruce]

try stuffing the clean out with insulation as a try to see if its leaking cold air inside, my garage cleanout leaked like that

 

[GaryS]

Here's a couple pics. I can get more info later. I'm heading out tonight for a couple days. My son and I are going to spend a couple days at the homeplace in the backwoods and do some deer hunting. Hopefully, someone left me some dry wood in the basement.

Someone will be disappointed if the stove goes offline. You can see all the nasty creosote on the brick. I'm going to clean it as best I can when I find a solution to this.

Here's where the pipe from the stove goes into the wall. An adapter steps it up to 8". I measured it. I'm going to be shopping for some 6" SS lining. I'm still not sure how I'm going to connect it up in the tee that's on the outside of the basement wall. I'll have to sketch that out.

 

[struggle]

Holy crap I would not burn in that until you get the creosote problem fixed. That is a chimney fire waiting to happen if it is coming from inside that pipe. Does it stink terrible when it is coming out? Mine did but leaked nothing like that :ahhh:

 

[GaryS]

Yeah, it's pretty nasty. The flue is actually pretty clean. I was assuming that it was water that runs down the pipe through the creosote that collects in the bottom of the clean out and comes out black. The other morning, it was mostly clear water coming out.

I'm going to start cleaning this up when I get the liner. Once I get the initial crud off, does anything help remove the stain off the brick? Bleach? Muratic acid? From experience, I know the brick will be permanently discolored.

 

[stop drop & roll]

I'm experiencing the same exact problem but not quite to that extent. My set up is similar to yours, except my 6" stove pipe connects to 8" thimble. I would like to put an insulated liner in, but not sure how I fit a 90 degree elbow where the horizontal and verticle run meets aprox three feet in wall. My set up now has the increaser after the 90 degree stove pipe, so the condensation runs out of the brick at that point. Would putting the increaser before the 90 degree help contain the condensation to the stove?

 

[GaryS]

I'm experiencing the same exact problem but not quite to that extent. My set up is similar to yours, except my 6" stove pipe connects to 8" thimble. I would like to put an insulated liner in, but not sure how I fit a 90 degree elbow where the horizontal and verticle run meets aprox three feet in wall. My set up now has the increaser after the 90 degree stove pipe, so the condensation runs out of the brick at that point. Would putting the increaser before the 90 degree help contain the condensation to the stove?

I'm wrestlin with that also. I wonder if I can connect a coupling with a hole precut in it to the flex liner. Lower the flex liner down the flue and try to push a 6" straight piece into it from the horizontal section. I guess another option would be to just drop the flex liner down to the top of the tee and reach in and seal around the liner with some rope or rock wool. I could still run a couple feet of 6" through the horizontal section.

 

[stop drop & roll]

Stove shop guy sugested I might be able to atatch a straightened 90 degree fitting to the liner, then manipulate back to 90 degrees inside flue. Anybody done this?

 

[GaryS]

I've got maybe 8" of clearance so this may work with a little filing.
(broken link removed to http://www.northlineexpress.com/itemdesc.asp?ic=5SP-4667)

 

[stop drop & roll]

Why would you need a double wall insulated tee? Wouldn't a single wall tee work with the liner insulation? I would have to fabricate my tee to not have a bottom. That might work, thanks.

 

[GaryS]

That was the only Tee I found for now. Where can I find one that's not insulated?

Is there a problem joining a regular steel pipe to SS? I know that some metals don't like each other.

 

[GaryS]

maybe insulating the cavity with vermiculite?

I was wondering that also. That would get rid of any airspace around the pipe and hopefully prevent condensation of ambient air moisture. Wouldn't take much to fill that space.

 

[stop drop & roll]

I was also told that all you have to do is insulate the top and bottom of the liner and let the airspace act as insulation in the middle. But thats why I'm here caus I don't know. Maybee some pros could chime in. Thanks.

 

[stop drop & roll]

That was the only Tee I found for now. Where can I find one that's not insulated?

Is there a problem joining a regular steel pipe to SS? I know that some metals don't like each other.

(broken link removed to http://www.northlineexpress.com/itemdesc.asp?ic=5SP-7183)


Here's a single wall tee stainless

 

[GaryS]

That was the only Tee I found for now. Where can I find one that's not insulated?

Is there a problem joining a regular steel pipe to SS? I know that some metals don't like each other.

(broken link removed to http://www.northlineexpress.com/itemdesc.asp?ic=5SP-7183)

Here's a single wall tee stainless

I saw that one. There's no way I can get that inside the flue unless I cut most of the horizontal pipe off. Maybe that would work.

 

[jabush]

You shouldn't have to cut anything. The snout on that Tee is connected with a band. You take the snout off and reattach it (through the thimble) after you drop the liner down the chimney. You can then run regular stovepipe from the Tee to your stove collar. Shouldn't be too hard unless I'm totally missing something.

That was the only Tee I found for now. Where can I find one that's not insulated?

Is there a problem joining a regular steel pipe to SS? I know that some metals don't like each other.

(broken link removed to http://www.northlineexpress.com/itemdesc.asp?ic=5SP-7183)

Here's a single wall tee stainless

I saw that one. There's no way I can get that inside the flue unless I cut most of the horizontal pipe off. Maybe that would work.

 

[Jimbob]

Many liner kits have a tee with a detachable snout. You push the snout through the thimble and attach it with the supplied stainless screws, working through the snout.

A variety of the tee is pictured in this kit:
(broken link removed to http://www.chimneylinerdepot.com/store/comersus_viewItem.asp?idProduct=312)

[EDIT] I see the tee linked by a previous poster is the same type as the one I just linked to...