creosote icicles

[DavidJinPa]

Hello Everyone
I'm new here, and thought I'd asked the more experinced too possibly answer an issue I'm having with my new stove, and chimney. We recently (this past winter) had a chimney fire, it wasn't bad but opted for me too replace my old setup. We had a new chimney put up (8" tile lined 8" thimble), and installed a Harman SF 2500A wood/coal warm air furnace (uses 7" stove pipe). This system limits the damper thru the thermostate too control the stove temperature. But I've bypassed this setup because it was snuffing the stove too much, and we were getting a very dirty chimney consisting of glazing, and moisture. Including making black icicles up top of the chimney outside. I've been running the setup much hotter constantly, not letting it snuff itself. But still have moisture collecting (freezing/dripping) outside at the top of the chimney. It's still creating black icicles at the top, but not quite as much. I know my wood is seasoned very well, and dry. I've attached a pic of the mess. What the heck could be causing this issue. This is driving me crazy. Anyone have any insight? It would be greatly appreciated.

DavidJinPA

 

[Michael6268]

Wow! Not the kind of icicle I would want to break off and eat when I was a kid. How hot are you burning? Are you absolutely sure the wood is seasoned and not wet?

 

[DavidJinPa]

Stove pipes reading around 325/350. The wood is good, and seasoned too.

 

[MrGriz]

Where are you taking the temperature reading of the pipe? If the 325 / 350 temp is near the stove, I don't think you are running hot enough.

Let me start by saying that I am not an expert and I didn't stay at a Holiday Inn Express last night. I think creosote will form at temps below 270. When you are burning, do you see smoke coming from your chimney? When I get up to temp, I can go outside and see nothing but a bit of a heat signature coming from the chimney, no smoke. I would bet that the top of that chimney is well below that and that the screen is getting plugged up and collecting creosote. Burning hotter may help.

Again, are you sure your wood is well seasoned and dry. My neighbor had a similar problem with creosote dripping down the outside of his chimney last year. The cause was finally tracked back to unseasoned wood.

Edit: BTW, welcome to the forum, I'm sure there will be more experts here to help soon.

 

[DavidJinPa]

Thanks Griz.. I cranked her up too 375/400 (guess more or less) and she dried up in a day... I still think I'm going too go over too harbor freight too grab a moisture meter for saftey sake, and edjumicational reasons. Though,,,Now I have a problem with burning a large amount off wood. Plus I'm only getting about a 5 hour burn down too a bed of hot coals. Think she'd burn out totally in about 6/7 hours if left untouched. I ordered a flue gas thermometer so I can fine tune this bugger for better/longer/more efficient runnning time. I hope someone on here is familiar with this type of set up, because the 2 local places that sell them "don't have the time too help me with it". Any help would be a greatly appreciated....

DJinPA

 

[MrGriz]

Glad to hear that you are moving in the right direction.

When you check a split with the moisture meter, you want to re-split it to get a reading from the center of the wood (hopefully that made sense).

Keep us posted.

 

[Andre B.]

When you check a split with the moisture meter, you want to re-split it to get a reading from the center of the wood (hopefully that made sense).

Keep us posted.

Basically if you use/(play with) your meter a lot you are going to end up with a lot of kindling.

 

[struggle]

I had the exact same problem you are having with a 8x8 Clay tile exterior chimney and also had a chimney fire a few weeks ago.

I chose to reline the chimney with a 5.5 316 flex liner and now all the problems went away. I am running now a Hearthstone Mansfield and after week of burning I looked into the pipe connection going into the wall and it had just a fine black powder on the insides of the liner. No shiny creosote. With the clay tiles there is just to much moisture getting into the chimney like you are experiencing as I did.

I used to have the black ice like you show and the heavy staining on the chimney. I am betting you have air infiltration some where in the chimney.

 

[DavidJinPa]

The majority of the wood tested around 15/20%. I'm guessing the wood wasn't/isn't the problem. At least I can keep track of that for now. Thanks for the masonary heads up too! I'll post more discoverys, and questions soon I'm sure. Tired for now. Thanks for all the insights...
Posted a pic of the beasty for ya's too

 

[DavidJinPa]

front view

 

[laynes69]

I've looked at those furnaces before. Does it heat well, and have you tried anthracite coal? If you have a forced draft than 5 to 6 hours would seem good. Its been in teens and single digits at night. Our forced draft has ran almost constant, and the thermostat upstairs is set at 72. I load it well at 9:00 and I have to reload it at 2 or 3 am or by 5am the furnace will just have a few coals in it. The forced draft burns more wood, but the heat is needed in this weather. Normally I get a good 8 hour burn with ours. Burning it a little hotter will make a good difference. Those units look nice and seem well built.

 

[DavidJinPa]

Yea Laynes this things built sweet. Super quality craftsmanship. She's a tank. My last unit was a 30 year old Glenn Wood wood furnace built in Lititz PA. This things like a Cadilac compaired too it. This unit does have a natural draft, but is increased electronically (opening more) by demand from the themostate. Our house is 1500sq ft so it really dosn't demand too much from the stove via the thermostate. Most of the time it kicks heat automatically thru the ducting when the plenum reaches 160deg. Once the plenum reaches 130 the blower shuts off. We've been having 9 too 15deg nights, she's easily kept the houses core temp at 75, and out rooms in the upper 60's. We've hit low 80 in the mid 30's.. Thats with our incorrectly undersized ducting too.. I think if we had the correct ducting thru the house I could get the house up too 90 no prob, lol.. I haven't had the time too experimnet with the coal thing yet... I believe (guessing coal needs less air) it would burn coal more efficiently but I get my wood for free. I think I'm going too have to modify the damper on the front too. The two holes on the front of the damper door don't give it enough air too keep the wood fire hot enough, and it smolders badly. Manufacturer says they do, but they don't. Thats whats caused the icicles for sure. I believe I'm going too have too tap a set screw into the damper door, so I can tune it (cracking it open 16th"too 1/8") for best burns with wood. This ones really go me thinking. But like I've read here, burning woods an art not a science.... Funny, but True..

 

[elkimmeg]

do you have an ash cleanout door? I have seen similar problems with cool air leaking by the ash door and cooling the exhaust gasses and condensation occures similar to what you are experiencing..

Might I note, 26 gage single wall galvanizerd pipe should not be used for wood fired appliances or coal fired .It is ok for an oil or gass burner but not for wood your flue temps get high enough the Galvanized coating will emitt toxic fumes. 26 gage is also not adequate for wood burning appliances code requires 24 gage stove pipe not galzanized

As an experiment I would loose the cap the Cap prevents the normal flow upward and the smoke looses momentum and hitting cold air condensates to cresote form

Just another suggestion. The simmilar ones I investigated. the problem was found to be ash cleanout door leakage The people just caulked it shut, the problem went away

 

[Roospike]

Good points ole' "Eagle eye Elk" .

do you have an ash cleanout door? I have seen similat problens with coo air leaking by the ash door and cooling the exhaust gasses and condensation occures similar to what you are experiencing..

Might I note 26 gage single wall galvanizerd pipe should not be used for wood fired appliances or coal fired It is ok for an oil or gass burner but not for wood your flue temps get high enough the Galvanized coating will emitt toxic fumes. 26 gage is also not adequate for wood burning appliances code requires 24 gage stove pipe not galzanized

As an experiment I would loose the cap the Cap prevents the normal flow upward and the smoke looses momentum and hitting cold air condensates to cresote form

Just another suggestion. The simmilar ones I investigated. the problem was found to be ash cleanout door leakage The people just caulked it shut problem went away

 

[BrotherBart]

Unless if it is stainless.

 

[reaperman]

Hey Laynes 69

You mention you use your forced draft unit runs almost constat. Doesn't your wood furnace get way too hot getting that much air? This is my first year with a wood furnace (fire chief unit). At first I used the forced draft blower with a seperate thermostat on the main level of my home, just like the instructions say. But that much air just seemed to get the furnace way too hot. I've since stopped using it from early on and just used the damper on the ash door, along with the slider on the forced draft blower to control the fire. It seems to work fine, the plemium blower runs most of the time there is a good fire. I have the settings at 150 on, and 90, off.

DavidJinPaI
It appers your plenium blower isnt connected to a cold air return, does it seem to work ok that way?

 

[Roospike]

Photo Edit:

 

[DavidJinPa]

Too respond too some of this let me start off with the quotes. So we (I) don't get confused,lol

(1) "Do you have an ash cleanout door? I have seen similar problems with cool air leaking by the ash door and cooling the exhaust gasses and condensation occures similar to what you are experiencing"

(1a) No clean out door is present. Their is a 12" deep trap below the thimble, the pipe must be removed too clean it out. I've taken a lighter flame, and gone around the pipe at the thimble. Some air (enough too pull the flame into the crack) is leaking into the thimble, would this be enought too cause problems? What kind of "caulk" could I use around the stove pipe that would handle that temp.?

(2) "As an experiment I would loose the cap the Cap prevents the normal flow upward and the smoke looses momentum and hitting cold air condensates to cresote form"

(2a) I started originally operating the stove without the cap, and had the creo problem. Since I've put it on it, and it isn't running at high output with the cap I've noticed condensation on the bottom middle of the top section of it. This really has me boggled. I'm worried rain/snow would enter, and increase this problem..

(3) "You mention you use your forced draft unit runs almost constat. Doesn’t your wood furnace get way too hot getting that much air?"
(3a) No forced draft is present, it draws air naturally. (see pic attached) the thermostate opens the draft if more heat is needed increasing the fire in the box. This rarely happens due too the temps it keeps the house just by regulating temps in the plenum.

(4) "It appers your plenium blower isnt connected to a cold air return, does it seem to work ok that way?"
(4a) As the stated above "The ducting through out the house is undersized". The ducting pro's I've spoke with recommended I run it off, and leave as many doors inside open leaving a "natural" draft down the cellar steps. Seems too be working fine, except when an a outer rooms door is closed. It does get slightly cooler in that room. Not bad though. They said the return duct would possibly under limit the air going too the blower motor, and could over limit it. Plus restrick flow back into the house. (thats a whole other project,, argggg)

 

[laynes69]

When the sun comes out, the house warms up a little. By the time we go to bed the house is 75 and somwhere in the night when the house drops to 72 then the forced draft kicks in. It will run almost constant in the morning when its 0 to 10 out. It gets enough air that it won't overfire the furnace. Plus if it would it has a limit to kick the draft off. Its in the rear of the firebox above the fire so its not blowing directly on the fire itself. That would overfire it. When it's warmer out 20 to 30 the forced draft wont run at all. When I wake up the house is warm and the furnace is full of coals. Now when its cold out when I wake up there are onl a few coals left and the drafts running. It knocks down the burn times by probably 2 hours, but keeps recovering heat faster so the house stays warm.

 

[reaperman]

Laynes69

My forced air blower is located under the main firebox door, so when it blows, it blows directly at wood level, sometimes under the wood piled in the firebox, depending on how much wood is in the unit. So you can see why I'm discouraged from using it. Although I do use it occasionally to get a fire up and going.

DavidJin

Wood furnaces aren't exactly noted for high efficiency and aren't EPA regulated, although I wish they were. So they do tend to eat their share of wood. Your burn times arent much out of line with mine. I've been burning larger rounds (8")
of oak at night, during these subzero temps that have been lingering for a couple of weeks now. This will leave me with coals in the morning, (8hrs). But thats a full load each night. I do have a brand new home, with excellent insulation. So the heat will linger throughout the day until around supper time when I fire it up again. I dont always like lighting a new fire each day, so sometimes I'll throw a few pieces in to keep a bed of coals going so I dont have to start from scratch each night. Which I know isnt the best for the chimney, and yes my chimney cap is getting black because of it. So in the long run, I believe I'am saving on wood by being able to let the fire die in the morning. Unlike my old home where the woodstove was blazing constantly. One benefit of the wood furnace is the even heat throughout the home. I miss the radience of a woodstove, but I do enjoy the even heat.

 

[DavidJinPa]

[quote author="reaperman" date="1171229073"]Laynes69

"My forced air blower is located under the main firebox door, so when it blows, it blows directly at wood level, sometimes under the wood piled in the firebox.
Your burn times arent much out of line with mine. I've been burning larger rounds (8")
This will leave me with coals in the morning, (8hrs). But thats a full load each night. /quote]
Reaper I'm only getting 5hr burns and its out. Not 8hrs. Also I don't have a blower itno the fire bx. Confusing me here now!
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>
Anywho. Its been a week since last I cleaned it, and the temps actually in the lower 30's today so I thought I'd see whats collected. Also I've cranked her up hotter, and the only really bad thing I found was about a 1/8th inch of liquid creo in the bottom of the trap. No creo flakes or anything else in their just the syrup like liquid. (picture attached).. The liner (picture attached) wasn't really even worth running a brush down, but I did it anyhow too see what collected. Wasn't much of anything. The top of the chimney did have a solid glazing outside on it (picture attached) from where it was I guess rolling inside the cover before escaping it. I removed the cover for now too experiment, and see if it's better without as mentioned above..

 

[DavidJinPa]

Rest of the pics

 

[elkimmeg]

whow lot of cresote in that chimney looks pretty dangerous. I hope you got it inspected and forwarded the certificate of inspections to your insurance company?
The ash door I speaking about, is the one built into the chimney while you furnace is pulling use an insense stick and see it it is pulling in smoke
around that door

You can also seal around the vent pipe with squeze tube gasket cement or caulking tube of refractory cement either or has a temperature that works.

you might as well not caulk till you use the proper vent pipe and loose that galvanized pipe/. I willing to bet a permit was never pulled and it was never inspected
No inspector should have missed the glavanized pipe.

 

[BrotherBart]

Rest of the pics

Line that chimney guy. I looked down the two holes in mine at that "popcorn" burned creosote for years. Lined the suckers this year and have nothing but fine brown soot. That thing is a clean straight shot and you can get a liner for under four hundred, delivered. Do it for the piece of mind and easy cleaning if nothing else.

And you ain't gonna believe the increase in performance from that furnace with the improved draft.

 

[DavidV]

Well I have to side with BB. What is the spec chimney size supposed to be? also I havn't seen what your chimney length is. I suspect a combination of shortt run for chimney length and oversized chimney. There may be other issues but these can't be helping.