Rookie with creosote question

[Big_Al]

My question involves my daughters woodstove. She bought a new Napoleon woodstove in the fall of 09. We installed it in her house into an existing chimney, the chimney was inspected by a local chimney company and they said it was ok. She burned last year and within a month or so had major creosote buildup, (1-2 inches) mostly in the section above the stove. It is about 4 ft long and has a 45 deg angle (approx) on each end. She is having the same problem again this year, we are having to clean it every month.
Her wood comes from our wood supply that was cut and stacked in fall/winter of 09, mostly tamarack and red fir. It is the same wood we burn and our chimney is almost creosote free. She runs the stove in accordance with the owners manual and some advice from me and my father in law. Nothing seems to help. Looking for advice on things to try, I don't like chimney cleaning and definetly don't want her to have a chimney fire.

 

[Wife'nHubby]

Did you line the chimney with 6" SS? Did you follow the 10/2/3 chimney rule? Did you insulate the lining? Is the chimney interior to the home or exterior to the home? Do you have 1/4" rise per foot in the interior 4' section?

Shari

 

[mga]

is the existing chimney on an outside wall?

like Wife'nHubby said, it should have been insulated. usually that amount of creosote happens when the gases hit a colder surface.

 

[Wife'nHubby]

PS: The 10/2/3 rule is here: http://www.fireplacesnow.com/smchinfo.asp

Shari

 

[LumberjkChamp]

Is there a thermometer on the stovepipe? If not, that is like driving a car without a speedometer. I understand you said the stove was being run in accordance with the owners manual, but there are only a few things that cause serious creosote buildup as you described: Low stack temps., green or wet wood, or an improper install.

If the wood is dry and the install is sound (outlined in Shari's post above) the situation precludes most of the major possibilities of excessive creosote formation, except for a stovepipe that does not reach acceptable temps. when the stove is running.

 

[CrappieKeith]

Is there a thermometer on the stovepipe? If not, that is like driving a car without a speedometer. I understand you said the stove was being run in accordance with the owners manual, but there are only a few things that cause serious creosote buildup as you described: Low stack temps., green or wet wood, or an improper install.

If the wood is dry and the install is sound (outlined in Shari's post above) the situation precludes most of the major possibilities of excessive creosote formation, except for a stovepipe that does not reach acceptable temps. when the stove is running.

a lack of combustion make up air to the home can also be the culprit.

 

[mowoodchopper]

sounds like a cold spot to me, cold flue means build up

 

[Wife'nHubby]

a lack of combustion make up air to the home can also be the culprit.

Very true, CK - and if the problem is related to lack of combustion air she should be experiencing low stove temps. Without any info on what temps she's running at we are all kind of punting here.

To the OP: - Need more info, please. -

Shari

 

[LumberjkChamp]

a lack of combustion make up air to the home can also be the culprit.

That is true. Good point.

 

[CTYank]

My question involves my daughters woodstove. She bought a new Napoleon woodstove in the fall of 09. We installed it in her house into an existing chimney, the chimney was inspected by a local chimney company and they said it was ok. She burned last year and within a month or so had major creosote buildup, (1-2 inches) mostly in the section above the stove. It is about 4 ft long and has a 45 deg angle (approx) on each end. She is having the same problem again this year, we are having to clean it every month.
Her wood comes from our wood supply that was cut and stacked in fall/winter of 09, mostly tamarack and red fir. It is the same wood we burn and our chimney is almost creosote free. She runs the stove in accordance with the owners manual and some advice from me and my father in law. Nothing seems to help. Looking for advice on things to try, I don't like chimney cleaning and definetly don't want her to have a chimney fire.

No matter what I think is happening within a stove, especially while sorting out system and procedures, I rely heavily on visual feedback.

Meaning, look at the quality of the exhaust. Smoke is bad. Any smoke. Note whatever you did to cause smoke, and whatever you do to clear it up. Avoid the former & pursue the latter.

And, yes, you really need a thermometer, if only to be able to determine when the stack is up to temp.

Tout simple.

 

[CrappieKeith]

Does the flue diameter match to what the manufacture calls for?

 

[Big_Al]

Lets see if I can answer all of the questions.
She has a thermometer but wasnt sure where to place it due to the angle/joint piece that is coming out of the stove. She had it attached (magnet) to the pipe but resting on the top of the stove, normally reads 500-600. The first section out of the stove is a 45 angle joint, second is an adjustable 6" sliding section about 4 ft long, third piece is another 45 angle joint that connects to the stovepipe coming out of the ceiling. Goes out thru a 4ft crawlspace, then out the roof and is 4ft above the roof. Near as I can tell her set up meets the 10/2/3 rule. Only part of it she may not meet is the 15 ft recomendation for stovepipe and chimney length. The part going from the ceiling to the roof is pipe with cinder block around it, above the roof is all triple wall pipe. The inside pipes are all single wall. Wood should be plenty dry, cut and stacked for at least a year and in this climate I would think that is plenty. We burn the same stuff and have no issues. Hope that covered everything, if not please ask.

 

[logbutcher]

All systems sound fine, except the obvious: use. Flue is good, wood is fine, stovetop temps sound good, but-----

Many damp their stove down too soon, before the wood reaches the coaling and gas state. True when not much heat is needed. It's a normal reaction by many users.

The load needs time to get up to pyrolysis or efficient, clean burns.

Also, most have a daily morning "hot burn" to "burn off" the accumulation of any flue deposits from a nightly slow burn.

Bets are on.

 

[pook]

1- check for air leak @ stove collar & fluepipe connection & if there's a key damper in the flupipe that its open. Cold also be that the seam where the pipe snaps together is leaking?
2- guess= she's starting lotta fires in cold stove improperly so that the kindling gets going & she adds wood which results in kindling getting smothered & lame flame + smolder which would rise into the cold pipe & condense.
make sure startup fire establishes well & crack door if necessary but dont forget it.
Me loves carrdboard & k2 but i know how to use it.....firestarters might be worth a try also...good lux

 

[CrappieKeith]

All systems sound fine, except the obvious: use. Flue is good, wood is fine, stovetop temps sound good, but-----

Many damp their stove down too soon, before the wood reaches the coaling and gas state. True when not much heat is needed. It's a normal reaction by many users.

The load needs time to get up to pyrolysis or efficient, clean burns.

Also, most have a daily morning "hot burn" to "burn off" the accumulation of any flue deposits from a nightly slow burn.

Bets are on.

Great advice....as to Pook..:notrolls2:

 

[Wife'nHubby]

Lets see if I can answer all of the questions.
She has a thermometer but wasnt sure where to place it due to the angle/joint piece that is coming out of the stove. She had it attached (magnet) to the pipe but resting on the top of the stove, normally reads 500-600. The first section out of the stove is a 45 angle joint, second is an adjustable 6" sliding section about 4 ft long, third piece is another 45 angle joint that connects to the stovepipe coming out of the ceiling. Goes out thru a 4ft crawlspace, then out the roof and is 4ft above the roof. Near as I can tell her set up meets the 10/2/3 rule. Only part of it she may not meet is the 15 ft recomendation for stovepipe and chimney length. The part going from the ceiling to the roof is pipe with cinder block around it, above the roof is all triple wall pipe. The inside pipes are all single wall. Wood should be plenty dry, cut and stacked for at least a year and in this climate I would think that is plenty. We burn the same stuff and have no issues. Hope that covered everything, if not please ask.

What pitch does she have in that 4'?

Now, as to minimum chimney height: Guys, help me with this- for each angle you subtract how many feet off height? Example if she's got 12' straight up, plus 4' horizontal you would think there is 16' - but no - you have to subtract footage because of the two 45's.

You say she's burning the same wood you are. Are you burning a newer EPA stove? Older stoves aren't so picky about moisture content in wood whereas newer EPA stoves are. I'm assuming her stove is a newer EPA which is looking for a moisture content of something less than 20%.

Shari

 

[ihookem]

I don't think your chimney is getting hot enough. It doesn't sound like your 6" flue is going all the way to the top. It seems you are using a stone and clay flu that isn't getting hot enough. I think the wood you are using makes lots of creosote anyway.

 

[CrappieKeith]

What pitch does she have in that 4'?

Now, as to minimum chimney height: Guys, help me with this- for each angle you subtract how many feet off height? Example if she's got 12' straight up, plus 4' horizontal you would think there is 16' - but no - you have to subtract footage because of the two 45's.

You say she's burning the same wood you are. Are you burning a newer EPA stove? Older stoves aren't so picky about moisture content in wood whereas newer EPA stoves are. I'm assuming her stove is a newer EPA which is looking for a moisture content of something less than 20%.

Shari

starting with a 45 she has a great pitch in the pipe ,but you may have hit on something Shari in your last paragraph.

 

[Wife'nHubby]

(off topic) "carrdboard & k2" = again - BAD advise - DANGEROUS advise - not allowed per manufacturers spec, may damage your stove & void your warranty. But if you are burning a sawdust furnace or a modified pellet stove with a minnow basket filled with sawdust that you refill with a shovelful of sawdust every 1/2 hour and vent with galvanized pipe.... well then, do what you want.

(on topic) In this thread we are speaking of a modern EPA wood stove that the owner is attempting to run per manufacturers specs. Let's keep the good thoughts flowing and sort out the unsafe stuff.

Shari

 

[Wife'nHubby]

starting with a 45 she has a great pitch in the pipe ,but you may have hit on something Shari in your last paragraph.

Keith - What's that 'rule of thumb' where you loose "x" number of feet for each angle?

Shari