Creosote Incident

[jlow]

Just put a damper on my stovepipe Saturday. Today, my wife calls me and says brown liquid is running down my stovepipe. It is entering at the adapter to the chimney. Any help in this matter. Went on the roof and the top of the chimney is got some build-up. It is smoking from the existing burn but now I I have shut down the stove. I think I need to do a big burn to clear out existing creasote. Opinions please. Rookie that I am, I need to make sure I solve the issue.

 

[edthedawg]

jlow man - you just got that Big Boy and already gunking it up???

First off - refresh us on your wood selection again? How has it been seasoned? what species?

Second off - tell me you are running wide open every day for at least 20 minutes?? That "big burn" every day should minimize such buildups.

You added the damper which is great - keeps the firebox hotter longer - right? well the compromise is you now slow down and COOL down the flue. That's bad, mmkay? You gotta run it fast and furious every day.

And you sound like you have the pipes installed upside down if you are getting creosote globs running down the pipe - it should all be male joints pointing down to contain that...

 

[cgeiger]

EdtheDawg is right on - hit us with your wood and how long it's been outside cookin' Also, how tall is your chimney and is it lined?

Liquid creosote is always a product of condensation. From what I've read here that is typically a product of hot gasses (including the precursors to creosote) from your stove hitting the cold air, and especially the sides of, your liner. As they interact with another, condensation forms and "mixes" with the creosote forming the stinky brown liquid your wife is seeing. In order to prevent this you need to manage your draft, fuel, and combustion environment in order to get your liner/chimney heated as fast as possible and then keep it warm (in addition to a good burn). By adjusting these variables you can counteract for small deficiencies in any one variable.

To keep it from dripping down, make sure your joints are oriented correctly as EdtheDawg pointed out - male should always be pointing toward the stove.

In short, a good hot fire when you crank her up for the first time each day will help get your draft started strong - managing your fuel and combustion air will keep it that way. Then, no more liquid goo.

 

[kenny chaos]

I hope I'm not too late.
DO NOT have "a big burn to clear out existing creosote."

 

[edthedawg]

His original post: https://www.hearth.com/talk/threads/33633/

Looks like a nice install but all exposed indoors. Can't tell what happens up above... Seems like a classic case where he can just run hotter every day and burn the snot out of the pipe... But the wood ain't helpin! Since he was getting such good firing, nobody bothered to ask in the prior thread!!

 

[jlow]

I have been burning ash and oak been in my yard for 2 1/2 years. It burns well. The stovepipe is as directed. The "goo" came through at the top seam of the adapter where it twists in at the chimney support. This is the Selkirk chimney set-up. I am, in hindsight, confident that the method of dampering the stove has led to this issue. I have had big burns but not with the damper completely open. I do close the damper at night when burning slow. This is where the cooling of the chimney takes place. What is next step? You say not to burn a fire yet

 

[savageactor7]

When you do burn again I wouldn't close the damper more than 45*.

 

[edthedawg]

In a "normal" fire - up til now anyways - how soon after loading would you close the damper? and you'd close it all the way, right?

I'd suggest a cautious buildup here - don't pack it to run a big fire. Load a few splits and run it wide open to load, like normal, and then really slowly bank it down. Don't close it all the way, and don't be afraid to run thru that load hot. Leave it halfway closed at most for the next couple fires - hopefully you see no more gunk.

You have a probe thermometer? IR gun? You're gonna want to see 1000-ish flue temps sustained for awhile.

I think if you can run wide open for 15-20 minutes/day, every day, you'll nip this problem early. You'll still run closed & cool at night, but burning it all out every morning should take care of it...

 

[jlow]

The chase does run outside. It is insulated. Temps are in the low teens at night. Do I burn when I get home. When can I burn big?

 

[edthedawg]

if it were me, here's what I would do. I'd burn a mid-sized hot fire w/ the damper open and let it burn thru without closing the damper past halfway. I'd be monitoring my flue temps to try and keep them under 1200. Tough for me to guess what your big stove is capable of heating the flue up to...

I would do that as many times as it took to burn without creating any new gunk flow.

And then I'd do it one more time.

And THEN I'd adopt the "burn hot for 20 minutes in the morning to clean it out" method, and not worry about packing it full.

The risk is burning it right now w/ all that goopy, glazed, high-energy fuel in there. You need to burn that out without going so hot that it goes subatomic on you and burns your house down. Burn it without burning it - simple, right?? Well it ain't that hard - Run it hot enough to cook off the nasties without them all erupting in flames.

OR - call yourself a good sweep and get it checked out first. I hesitate to think what the sweep might say to do in its current condition...

 

[kenny chaos]

Sorry guys, I don't think I'm the paranoid type but without seeing it, I would never suggest burning out existing creosote. If there's too much already present it's like saying"start a chimney fire."
Maybe I'm missing something here. I seem to be out of the loop. Don't anyone panic.

 

[edthedawg]

Kenny - I hearya man. But think of it this way: The stove is what, a couple weeks old? he's got decent wood from the sound of things. And we have confirmed he's (unknowingly and unintentionally) just recently started running it too cold in the stack. I seriously doubt he's gunked it completely up to the point of danger in one week. He's just seeing the first signs of liquid condensation running down the pipe, and caught that early on.

Come to think of it, a good probe thermometer should be able to tell him that he's been underfiring the flue.

But regardless - burning it out like this is the widely-recommended way to keep a flue clean on a daily basis. And we're cautioning him to run it in a controlled state - not just pack it and leave it running full throttle. I say burn it carefully for a few fires, make sure the problem goes away, keep an eye out for sparks shooting out the chimney top and/or any chuffing sounds from the pipe... We know he can cool that flue down in a hurry w/ the damper if something does start up...

 

[jlow]

What is a chuffing sound? Will I notice any strange behavior from the fire in the stove if the chimney ingites? We will be home tonight and I would like to get this burn -off in process. It sounds like I may still see some residual goo tonight when I burn. I am thinking about dropping the pipe first to take a look at the point of drainage. What should I be looking for? It is a straight run up so I can see pretty good. Once again I appreciate all your input

 

[kenny chaos]

jlow- Glad I didn't throw a scare into ya. I went back and read the whole thread that Ed referenced and see you've been burning good temps and know what you're doing. I love the way you used your stove to define the different spaces. Very, very, nice. I'm just going to slink on outta here.....

Ed- Thanks for your patience and hey, better safe than sorry right?

 

[jlow]

So if I am getting this correctly, when I get home I am going to drop the pipe and take a brief look to see if I am going to burn my home down. Once I see the damage, I will re-fire with a small load burning hot for the evening. I will then leave damper open overnight and let it burn slow. I will know if goo will emerge by what I see when I tear it down. I knew I was burning cool when icicles were on my chimney cover. Does this sound like a good program?

 

[Highbeam]

My heritage owner's manual instructs me to burn a full throttle fire for 30-45 minutes every day! How about the EQ? That burns off any accumulated crud in the stove and pipe plus keeps the glass sparkly clear. I propose that the water running down Jlow's flue and into the space was just dirty water and not tar. So as soon as it dries it will be gone with no flue brushing required and no safety risk. The dribbles and mess on the hearth might be harder to clean up.

That said, during the first full throttle burn after not doing the full throttle burns regularly I would be around to react in the event of a chimney fire.

I wouldn't be taking the pipe apart. Way too much work.

 

[rydaddy]

For what its worth. I am on the same page. I load it up (the stove...duh) and it burns full throttle until the cast iron round top gets to 600ish 700. At this time my in-flue thermo reads approx 1000. Then I turn the throttle off, wait 10mins approx. Then shutdown the damper.

My stove is either running full bore or shutdown all the way. This is the only way it operates close to how it should.

 

[edthedawg]

600 in the center of the cast iron round plate on top is completely unheard of for me. That plate sits exactly at the same temp as the single-wall exit pipe out the back. The cast ring AROUND the plate, AND the stone immediately surrounding it, will get to 650 if I really push it, but it feels like the stove is gonna melt if I get that hot At those very hottest times, I won't see over 500 on the plate.

If I was running that cast plate to 600, I guarantee I would be overfiring my stove. At least that's how I interpret the manual...

I'll load up, burn full throttle / full damper til it gets really roaring (usu ~10-15m) and then another 10m or so usually with the damper and primary nudged just a little down (not even halfway closed), and then back both flue and primary to about 3/4 closed, if I'm heating or full closed if I'm maintaining temp for a longer burn (i.e. overnight / at work). If this is done on a hot coal bed, it'll get the stovetop (Rutland or IR therm @ top center stone, back near the cast plate but not touching it) to 500 consistently. It won't get over 450 on the first load from cold usually.

 

[rydaddy]

Fortunately, that top center plate is always hotter than my top center stone when the stove is really cranking.