Trouble With Woodstove

[GBertolet]

I am having a problem with serious creosote buildup. After 3 days of running, the inside 6" metal flue pipes are 50% clogged. The stove worked fine for the previous owner, so I believe the trouble must be in the venting. I am reluctant to further use this stove until I have this problem solved. I have good draft in the 27 foot high outside masonary part of the chimney.

The stove is a Riteway 2000. I do have three 90 degree bends in the flue pipe. One 90 degree bend out the back of the stove to go vertical 4 feet, then 90 degrees off to the side 4 feet, then one 90 degree inside the wall thimble to the masonary chimney. I think that this might be the problem. I can eliminate one 90, and make it a 45 degree instead. I don't know if that will do it or not.

I run the stove at 400 degrees, and it works alright otherwise. I burn the same firewood in my other stove inside the house with no issues. It's 2 year seasoned hardwood I am using. Any input or suggestions would be appreciated.

 

[On-Wheel]

let's see some pic's of this setup

 

[KRB52]

No stove expert, I don't even play one on tv, but I'm wondering if your pipe cools off too much for the run that you have. How does the flue for that stove look? Does it too get creosoted up or does it stay as clean as the other stove's flue? I'm just brainstorming here, maybe someone else with more experience can chime in.

 

[DonPowers]

Where are you measuring the temperature, top of stove or on the flu?

 

[GBertolet]

I am measuring the temperature at the side of the stove near the top. Here is a picture of my setup.

 

[Buckgnarly]

Looks like an awfully long horizontal run, put in a 45. According to my two stove thermometers, 400 is on the lower end but still in a good burn range.

 

[stihlntime]

When we have a draft issue we use the country solution instead of a chimney sweep. We take a log chain and tie it up in a ball with soft wire attach it to a long rope and up and down the chimney it goes until all the creosote is knocked loose. Then we clean it out. Once the flue is clean try burning your fire a little hotter. You have a long flue that might be cooling off and causing creosote build up.

 

[DonPowers]

Try taking the flu temperature just before it enters the chimney and see how much difference there is from where you are now taking it. If its the same, then you probably have a leak somewhere in the chimney, sucking in colder air.

Also, see the article below. Creosote forms at temperatures below 250 deg F.

http://www.hearth.com/econtent/index.php/articles/creosote_from_wood_burning_causes_and_solutions

 

[DonPowers]

Another question - Are you just bringing the stove to 400 deg with damper not fully open or do you let it burn wide open for at least a half hour or more before dampening it down?

Should go full throttle to heat the chimney before backing down. From my post above, the masonry needs to be above 250 deg to keep creosote from forming.

A little fire to take the edge off may not be enough to heat the chimney.

 

[Jackfre]

Wood is great when it is cold out. In the shoulder seasons you get the fire going and it just lugs along creating creosote. As well, your flue is marginal at best. I'd suggest a double wall vent connector. I'd come off the back with the 90 laid off at a 45 up to the 90 going into the chimney. You have 27' of masonry chimney. You would be far better off with a SS liner in that flue.

 

[mypov]

Burning the stove at lower heat encourages the build up of soot. Also, as others have mentioned the long horizontal run will also encourage build up. Also depends on what kind of wood you are burning, and how dry the wood is. You want hard wood, nice and dry ideally. The chimney is going to likely be an issue...Because it is run the way it is, it is best to go straight up, and the least amount of angles involved the better.

 

[dfiler2]

There is some good advice in the previous posts especially where the issue of having the stove dampered down this time of year is concerned. One thing I didn't see mentioned was the moisture content of the wood. After May 15 of this year EPA requires all wood stoves, including outdoor hydronic heaters, to include a moisture detector for the purpose of checking your wood. The reason for this is most people don't properly prepare their wood. There are some pretty inexpensive testers out there that work pretty well. Moisture content is really important to the efficiency of the stove, you can get wet wood to burn but a lot of the energy produced is used to dry out the wood. PM me if you are interested in an inexpensive tester and proper testing methods.

 

[gungatim]

as stated problem is likely with the flue temp...I'm no expert, but when I put mine in, there is a forum called hearth.com, those guys are freakin' experts on wood burning and proper setup, they are to woodstoves what this is to tools/garages. you may want to check over there for some real good technical info if you can't get it here (bet some of the guys there are on here though.)

 

[GBertolet]

The input I have received here reinforces my thought that the trouble is with the inside flue pipes. I will place a 45 degree bend at the thimble, which will shorten the run and eliminate one 90 degree bend. 45's are always better than 90's. I have done some research, and most experts suggest no more than two 90 degree bends, while I have three. Plus I will try running the stove hotter, maybe 450 or 500 degrees. I have a laser thermometer, so I can monitor the flue pipe temperature at various locations. I can then run the stove a week, shut it down, pull the pipes, and see what buildup I have, and take it from there. Thank you all.

 

[zak77]

It may be possible you're choking the fire too soon. I burn about 7 cords a year and only have to clean my chimney once a year and i don't have much creosote buildup. I'm running a metalbestos 8" double wall stainless up about 20'. My buddy had an issue one year where he had a bunch of birch to burn but he'd load it up and shut it down so the fire just smoldered and he had the same thing happen. I get my fire going really good before closing the vents down. I only burn well seasoned wood: oak, maple, birch, hickory. I dont use a thermometer but instead just go by feel. When the top if HOT i know it's ok to damp it down.

How's the draft???

 

[Highbeam]

That stove never was and never will be a clean burner. Modern stoves are designed to reduce the **** being sent up your chimney. Strike one.

The extra bends, extra long interior single wall pipe, with cold oversized masonry chimney will steal heat from your flue gasses which will then condense into creosote. Strike two.

Running that stove, or almost any stove at 400 degrees measured on the stove top is too cold. Those low stove temps are barely enough to keep the fire burning and will result in high emissions, low flue temps, and high creosote formation. Strike three.

Your best bet is to replace the pipe as planned with a very direct path. Then run that stove at 600. Next step would be a modern stove. Next would be a liner in the masonry chimney.

 

[930dreamer]

Is the chimney fully lined(stainless flex liner) all the way to the top cap? The horizontal run could be part of your problem also. Can you rotate the stove counter clock wise to align to with the chimney opening?

 

[DekeT]

I am measuring the temperature at the side of the stove near the top. Here is a picture of my setup.

Your stove pipe should not exit the building envelope lower than the highest heated space.

 

[TractorJeff]

UH? DekeT, what are you saying as I don't understand your wording in the statement?

 

[DekeT]

UH? DekeT, what are you saying as I don't understand your wording in the statement?

Take your pipe out the ceiling not the wall.

 

[brownbagg]

are you burning pine

 

[6768rogues]

I agree with GBertolet's comment that the first thing I would do is put a shorter pipe on a 45 degree angle to eliminate the horizontal run.

 

[rburke65]

When I started to burn wood I closed the damper to try to get longer burn times but the stack would clog with creosot quickly. I spent more time cleaning than burning I think. Very dangerous. Opened up that damper .... trial n error......hot enough temps now to keep that stack clear all year.

 

[walrus]

Your stove pipe should not exit the building envelope lower than the highest heated space.

Never heard that before. I guess I should have creosote up the wazoo but I don't so...

Too much stove pipe, causing the flue gas to cool down. You could try dbl wall stove pipe, it should keep temps up.

 

[DekeT]

Never heard that before. I guess I should have creosote up the wazoo but I don't so...

Too much stove pipe, causing the flue gas to cool down. You could try dbl wall stove pipe, it should keep temps up.

Actually more applicable to an area that you want to keep continuously heated. Still an appropriate design consideration. I have attached a couple links illustrating the effect of keeping the pipe location within the heated envelope.

http://www.gulland.ca/fhs/coldhearth.htm

http://www.hearth.com/talk/threads/recommendations-for-interior-or-exterior-chimney.6064/

 

[Highbeam]

Your stove pipe should not exit the building envelope lower than the highest heated space.

Totally false. Ignore this. There is no such rule. The majority of masonry chimneys run just like yours, up the outside of an exterior wall.

 

[DekeT]

Totally false. Ignore this. There is no such rule. The majority of masonry chimneys run just like yours, up the outside of an exterior wall.

BRILLIANT! Because you have seen this mistake made on most installations you ignore the science and installation instructions of the manufacturers because of your anecdotal observation. Chimney placement has largely been decided on perceived aesthetics and low cost versus good design. I said nothing about a "RULE". I said it was better design based on the science. What studies are you quoting while disagreeing with the links I provided?

 

[Highbeam]

BRILLIANT! Because you have seen this mistake made on most installations you ignore the science and installation instructions of the manufacturers because of your anecdotal observation. Chimney placement has largely been decided on perceived aesthetics and low cost versus good design. I said nothing about a "RULE". I said it was better design based on the science. What studies are you quoting while disagreeing with the links I provided?

Foolish, rubbish, troll. Trying to use big words so you look smarter.

The manufacturers of stoves all tell you how to hook up to a regular masonry chimney. There is nothing wrong with following code and the directions to reuse a masonry chimney if that masonry chimney is safe and legal.

I agree that an ideal chimney is not a masonry chimney at all. In fact, I prefer a premanufactured class A chimney, all vertical and as much as possible within the structure.

 

[DekeT]

I agree that an ideal chimney is not a masonry chimney at all. In fact, I prefer a premanufactured class A chimney, all vertical and as much as possible within the structure.

So you agree with me but insist on calling me names anyway. Maybe you shouldn't start blasting posters comments with worthless tripe before you do a little research and get some understanding of the topic. And I said nothing about the efficiency of masonry chimneys. My only statement on the topic was simply venting within the heated envelope. Which you decided was rubbish without really knowing the facts.