Creosote Problem

[mattaddington]

Aside from having a woodstove when I was a kid, I am a newbie to this. We just moved into a home with two Vermont Casting wood stoves.

I got up on the roof and cleaned both flues this fall and burned a CSL log in each. My first fire worked fine, but the second one filled the house with smoke after a little bit. After cooling, I took the stovepipe off to find the entry filled with a bubbly like crusty residue. I cleaned this out, got a great updraft and tried again. After about 45 minutes of good, hot fire, the same thing happened.

Anyone have any suggestions? Is this some sort of liquid creasote residue that runs back down the flue and bubbles up and cools at the 90 degree joint?

Thanks for any help! It's been below zero here all week and I would love to be heating the house a little!!

matt

I inserted a couple photos here for you to check out.

 

[savageactor7]

Oh my goodness ...you have to go back to square 1. Hook up with a wood burning neighbor that has some years of burning under their belt and ask for advice. Sorry to be so short.

Burn only seasoned wood but hotter around 550*...and forget about long burns.

 

[offroadaudio]

I'd say you have a huge safety hazard there. If it were me, I'd stop burning and not light again until I had a complete understanding of the problem and cleaned and did a thorough inspection of that chimney.
Here are the questions you will be getting, so get the answers ready:

1. Chimney - inside or outside?
2. Chimney - masonry or factory built?
3. Chimney - insulated or not?
4. Chimney - height?
5. Chimney - if masonry - terra cotta flue / lined with SS or not?
6. stove - what is the flue diameter of the stove? and does the stovepipe and chimney match it?
7. Wood supply - is it properly seasoned?
8. Burn technique - are you closing off the primary air early in the burn cycle?

The problem that you are having is caused by one or more likely, several of these factors - let's start to narrow it down.

 

[Malatesta]

It looks like whom ever owned the house prior to You and your wife never cleaned the flue ? And maybe never burned a hot enough fire in the stove. Now that your cranking it super hot ,it looks like the years of un-cleaned flue build-up are coming down into the elbow. Aside from that i'd have a professional chimney sweep come out and do a full inspection and cleaning.

 

[RedRanger]

Unfortunately, you can run the brushes up and down that chimney till the cows come home and it isn`t gonna do anything to get rid of that "glazed creosote". You are going to need a pro come out and use the special stuff to soften it and clean it properly, and it is probably going to take 2 or more repeat visits before he is done.

That chimney is much too dangerous to continue burning. So Stop!!

For your sake and your family`s sake-Get it taken care of ASAP!!

 

[Valhalla]

Aside from having a woodstove when I was a kid, I am a newbie to this. We just moved into a home with two Vermont Casting wood stoves.

I got up on the roof and cleaned both flues this fall and burned a CSL log in each. My first fire worked fine, but the second one filled the house with smoke after a little bit. After cooling, I took the stovepipe off to find the entry filled with a bubbly like crusty residue. I cleaned this out, got a great updraft and tried again. After about 45 minutes of good, hot fire, the same thing happened.

Anyone have any suggestions? Is this some sort of liquid creasote residue that runs back down the flue and bubbles up and cools at the 90 degree joint?

Thanks for any help! It's been below zero here all week and I would love to be heating the house a little!!

_______________________________


Welcome Matt,

Yikes! It looks like the previous owner burned, or tried to, wet wood and at low stove temps, since little or no heat could be produced. Probably a very good thing, as you would not want to heat up the chimney in that condition!

Have a pro stove store, sweep or, two or three, come in to give you some estimates. Do we see single wall pipe there? Let us know how it is all going.

You are in the right place here at Hearth.com!

 

[mattaddington]

Wow!! Thanks so much for the feedback and needless to say, I am glad that inquired here! The previous owner is 91 years old and claimed to burn quite often. But there must have been a lot of wet wood and lower temps like many of you said.

To answer some of those questions:

Chimney is interior.
Dual flues as the other stove is upstairs.
Both stoves are Vermont Vigilant casted in 1979. Not sure what the stoves flue diameter is. Chimney flue is about a 9" square?
Chimney is masonry (brick exterior)
Not sure if it's insulated? It is right in the middle of the house.
Flue looked to be terracotta as I was up cleaning it from the top.
Wood I was burning was well seasoned and very dry.
I was leaving the primary air supply pretty generous until about 450 degrees. Then tapered it off. That's when the smoke started.

Hope some of those things help. I am obviously not going to burn any more until I have someone look at it, but really appreciate you all sharing your knowledge and experience here! What a great forum!!

I really look forward to getting this fixed and again, appreciate your help in doing so.
matt

 

[LLigetfa]

The previous owner is 91 years old and claimed to burn quite often. But there must have been a lot of wet wood and lower temps like many of you said.

My father burned wet wood all his life until a chimney fire burned his house to the ground.

 

[offroadaudio]

Wow!! Thanks so much for the feedback and needless to say, I am glad that inquired here! The previous owner is 91 years old and claimed to burn quite often. But there must have been a lot of wet wood and lower temps like many of you said.

To answer some of those questions:

Chimney is interior.
Dual flues as the other stove is upstairs.
Both stoves are Vermont Vigilant casted in 1979. Not sure what the stoves flue diameter is. Chimney flue is about a 9" square?
Chimney is masonry (brick exterior)
Not sure if it's insulated? It is right in the middle of the house.
Flue looked to be terracotta as I was up cleaning it from the top.
Wood I was burning was well seasoned and very dry.
I was leaving the primary air supply pretty generous until about 450 degrees. Then tapered it off. That's when the smoke started.

Hope some of those things help. I am obviously not going to burn any more until I have someone look at it, but really appreciate you all sharing your knowledge and experience here! What a great forum!!

I really look forward to getting this fixed and again, appreciate your help in doing so.
matt

The Interior chimney is a good thing, that's a check in the plus column

The flue on the stove is most likely an 8" or 6" - the 9 x 9 of the masonry would be very oversized for 6 and slightly for 8, this causes the flue gases to cool when they expand to fill the new volume. This can be fixed with a full reline of stainless steel, which I suspect any sweep you get out there will recommend anyway. Based on what's there, that chimney has likely experienced a fire and so you can assume that the terra cotta is not in good condition.

If it's an interior chimney insulating a new liner is less critical, but still good for keeping flue gases warm to the top

Maybe let that puppy soar to 600 before starting to bank down in increments AFTER things get examined and cleaned.

Good luck - let us know what happens.

 

[Shari]

Matt,

You are getting some great advise here!

You mentioned the 2nd stove is 'upstairs'..... hmmm... not a good idea to have a stove in a room where people sleep.

Shari

 

[begreen]

If you are getting accumulations like this after cleaning either the wood is not seasoned or the stove is being run too cool.

Don't delay in figuring out what is happening, this is a potentially very dangerous situation.

 

[mattaddington]

Good deal...once again, great advice. I will keep you posted as to what I find out from a professional.

The upstairs stove is in a "commons" area between all the bedrooms. We're in a 125 year old 5 BR farmhouse. The stoves were added in the late 1970s.

thanks again.

 

[gerry100]

Ditto on stop burning until a pro looks at your set up.

We had a nearly tragic chimney fire in the early 80's caused by creosote piling up on the " smoke shelf" in the back of the fireplace. If your stoves are fed into old fireplaces , that could be your issue. Or any other turns or corners could also be the source.

These days, good steel line systems are available that will give you a better draft and much less hazard.