Cleaning Chimmney, How Often?

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scfa99

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Ok, i'm new to woodburning and want to make sure i'm doing things correctly. I've been up and running with my Quad 7100 for about a month. Burning seasoned hardwood (mostly black walnut, some ash, cherry and hickory). I usually run it pretty hot 400-600 stove temp, damp down at night but not all the way. I can't see up the pipe to check for buildup. So i'm wondering do i have the sweep come out once a year in the fall for inspection and cleaning or should have him come out during the season too?
 
I bet there's a way that you can check on creosote accumulation yourself.

Either way, I would check it out. Some installations can grow some serious creosote in a hurry while others don't produce any at all. It would be nice to know where you stand on that. It sounds like you know enough about creosote formation to come up with a cleaning strategy based on what you find out.

But consider doing it yourself, if possible. I like to clean mine once a week--whether it needs it or not. I sleep a lot easier knowing there's never going to be enough creosote in my chimney to cause a problem even if it does light off.
 
Eric,
We've talk at length about the risk that creosote presents, but I'm not sure what constitutes "serious creosote". The inside of my chimney is charred black, but it is just a film. When does it become a concern? 1/8" of an inch? One inch? When 10% of the flue is obstructed?
I know it is like cholesterol deposits in your arteries - less is better - but when does it become a dangerous condition?
Sean
 
DonCT said:
what good, if any do those CLR thingys do? Do they help at all?

Hey Don, I think you mean CSL ? (Chimney Sweeping Log)
I know that in some areas they are not allowed to use that label because in reality they don't "sweep" your chimney. I had a bit of build up that I wanted to clean before installing my insert and in discussing it with my installer he suggested I try one. My main chimney was pretty good, but I had some build up and slight glazing just above my ash shelf in the offset in a really difficult spot to reach. Installer mentioned that although he was initially skeptical, oiver time he had changed his opinion and thought they might help.

Did it? I think it did. It turned a lot of the deposits kind of chalky and white and it did seem easier to knock them down. A lot of it I reached with an old broom. Still had to sweep though.
For several fires after I used it, I also noticed a fine white ash falling like snow into my fireplace. Some I think was creosote, some I think was just he residue of the CSL.

Willhound
 
SeanD,

Well, in my experience, "serious" creosote would be pretty much a pipeful. If you stick a mirror in the cleanout and you can't see daylight (assuming it's day out and the pipe is straight) then you're in the "serious" category. Lots of creosote would be an inch or better, I guess. I always judge it by how much creosote comes out when I run the brush up the pipe. I wouldn't be comfortable if I was getting more than a gallon a week from my 25-ft tall, 8-inch ss chimney. Usually it's way less than that.

The more you have, the longer and hotter it's going to burn if it lights off.
 
Eric Johnson said:
But consider doing it yourself, if possible. I like to clean mine once a week--whether it needs it or not.

You're going to wear out your chimney scrubbing it that much! :)

I sweep mine twice a year which comes out to around once every two cords of seasoned hardwood. I probably get 1.5 gallons of ash, soot, and creosote out of my connector pipe, thimble, and 34' exterior 8x8 clay chimney each time I clean it.

Can you even measure the amount you get in a week?
 
Man, I've been burning for 13 years now and I have never had a chimney swept.

All four installations have been single wall in the house, and double the rest of the way through.

When I was new to this, I would get a ladder on the roof and peer down the pipe to check it out. Never more than a grey ash buildup. I still check them every month or so.

Eric Johnson is right, they are all different. Err on the side of caution until you understand your installation.

I usually check on the smoke output of my chimney every hour or so to make sure its not smokin'. I make adjustments based on what I see, usually there is no visible smoke. Do this simple check enough, and you will understand a whole lot more about whats going on in the firebox.
 
Oh, one more thing. In my house in WV, the winters are freaking cold. I did have a buildup around the mesh screen on the chimney cap. So, if you are in a cold climate, check out the externaly exposed part of the chimney.

Stay warm.
 
SCFA said:
Ok, i'm new to woodburning and want to make sure i'm doing things correctly. I've been up and running with my Quad 7100 for about a month. Burning seasoned hardwood (mostly black walnut, some ash, cherry and hickory). I usually run it pretty hot 400-600 stove temp, damp down at night but not all the way. I can't see up the pipe to check for buildup. So i'm wondering do i have the sweep come out once a year in the fall for inspection and cleaning or should have him come out during the season too?

I clean mine ss 3 times a year , Spet. January March. Never more than 2 handfulls of black flakes & dust after each cleaning. (poly) 6" round brush .
 
I brush mine once a year, and there is never more than a light ash.
My chimney is an over 25 foot stainless 6 inch single wall with ceramic insulation. It runs up a 11 inch fireplace chimney.
 
KarlP said:
Eric Johnson said:
But consider doing it yourself, if possible. I like to clean mine once a week--whether it needs it or not.

You're going to wear out your chimney scrubbing it that much! :)

I sweep mine twice a year which comes out to around once every two cords of seasoned hardwood. I probably get 1.5 gallons of ash, soot, and creosote out of my connector pipe, thimble, and 34' exterior 8x8 clay chimney each time I clean it.

Can you even measure the amount you get in a week?

I wouldn't call it scrubbing. I just push a poly brush up the length of the chimney and pull it back down (7" insulated stainless). Sometimes lots of creosote, sometimes none at all. After more than 10 years, I don't think the chimney is close to being worn out. The installation I'm talking about (my old house) burned between 10 and 12 full cords in a heating season. Pretty cold up here in the Adirondacks. The guy I sold the house to has been doing it that way for the past 3 years and I did it for 9 so that's what, 12 years?

I think a few chimney fires would do far more damage to the chimney than a regular brushing.

The set-up I have now produces zero creosote, but that doesn't stop me from popping the cap off the cleanout T once a week and giving it a good look-see. It's an 8-inch Duratech.
 
i use a csl log at the end of the season the very last burn. in both my stoves and about 3 to 4 weeks later what ever is in the chimney comes out 10 times easier. 3/4 of the creosote dries up and falls off on it's own.
 
Flue Bug said:
fbelec said:
i use a csl log at the end of the season the very last burn. in both my stoves and about 3 to 4 weeks later what ever is in the chimney comes out 10 times easier. 3/4 of the creosote dries up and falls off on it's own.

The last time I read the label on the CSL Log, there were explicit instructions against using them in a wood stove. Because of the density of the CSL Log, it burns at a very high temperature and can cause your firebox to warp from the heat. I've been to a few chimney fires that were caused by these things. I am not a proponent of their use in any solid fuel system.

looks like you haven't seen one in a while. i got the box in front of me. top right corner it say's for woodstoves and fireplaces & inserts. when i use them the stack thermometer only goes up to 325 for a short time. the stove doesn't throw a whole hell of alot of heat but it does throw a little and for about a hour and a half. then the log smokes for a couple of hours. if anyone plans on using one of the these logs don't use it one a windy day. because of the small amount of heat it makes it doesn't get the chimney to hot, so it has a good chance of backpuffing because of not a strong enough draft. if it does backpuff you can take it from my experience it smells a little like rotten eggs.

hey flue bug
if the low temp of burning this log caused a chimney fire would you agree they had some nasty buildup in that chimney? what might have caused those fires in my opinion would be buildup. when i burn these after a while the creosote buildup starts to flake and fall off. if a bunch of creosote builtup in front of the pipe from connector to flue and part blocked the opening that would start a blaze. that happened to me.
 
A few years back I bought one of those. Before I had a chance to use it I went to a chimney fire and the homeowner couldn't understand how it happened. He had been burning those things religiously, but never followed up with a sweeping. I brought it back, I brush my chimney anyways, and it isn't difficult. I inspect monthly, and clean annually. I never have more than a coating of dust. Some creosote on the cap. My only problem is that my brush needs some effort to go down the pipe. As a side note, I use CLR on my dishwasher to keep it clean, it works like a champ.
 
Gee, I didn't know there was such a thing a poly chimney brushes. I've gotten negligible stuff when annually brushing my 6" ss corrugated liner, two stories, (in an 8" ss prefab chimney), Quadrafire 2100 insert, 3-4 cords per year. I did feel that the steel brush might have been a little harsh though. Do the poly brushes work?
 
They work fine as long as you don't try to run the brush up the chimney when it's hot. Actually, you're supposed to use a poly brush with a ss liner. Steel brushes are for clay tile chimneys, as I understand it.
 
SCFA said:
Ok, i'm new to woodburning and want to make sure i'm doing things correctly. I've been up and running with my Quad 7100 for about a month. Burning seasoned hardwood (mostly black walnut, some ash, cherry and hickory). I usually run it pretty hot 400-600 stove temp, damp down at night but not all the way. I can't see up the pipe to check for buildup. So i'm wondering do i have the sweep come out once a year in the fall for inspection and cleaning or should have him come out during the season too?

I have to agree with Eric here. There is no hard fast rule. Burning seasoned hardwood is good start. Having a clean burning stove really helps. Burning shorter hotter fires can also help, smouldering, smokey fires can make it worse. Creosote is basically caused by the accumulation of the condensation of unburnt wood gases. One thing that will help mitigate creosote buildup is a straight (no bends) chimney on the interior of the house. Some things that will make it worse are poor draft, possibly caused by several angles in the flue path or a cold exterior chimney and the differential between the chimney wall temps and the gases passing through them. If you live in an extremely cold climate, some creosote seems inevitable, even with everything else working for you.

Like Sandor, I haven't had to clean our stack in 10 years now. I regularly check it, but it keeps showing up clean. But we live in a mild climate. And I really try to burn clean. I often check outside to see how we are burning and except for starting up cold and maybe 5 min. after reloading, there is no smoke.
 
What would you recommend for someone who will not get on the roof to check the chimney? My stove installers, also the chimney sweeps, said I only need to have it cleaned once a year (for the liner warranty). Do you think I should have it inspected more than once a year to check for buildup?
 
Flue Bug said:
There's got to be a way that you can take a look yourself without climbing.

1. Check the exterior pipe and cap. Are they discoloring in any way? Is the screen in your cap looking plugged?

2. Can you open the damper inside the stove and with a mirror and flashlight, check the pipe?
If there is any black glaze or fly ash that looks like "brown "oatmeal"its probably time to brush. As long as you can still distinguish the pipe joints from the rest of the pipe, your probably OK.

3. Is there a strong odor? Usually smells like burnt maple syrup? That's a good indication of developing creosote and that its time to brush.

When you find that your system seems to be getting dirty in a short period of time, you will need to examine your burning habits and be willing to make some changes.

And remember, that brushing isn't measured by time transpired, but rather by volume of fuel you've expired. You should be inspecting your system at least every 6 face cords.

My stove is new so no odors yet, I was just wondering how often to have it looked at. Is six face cords= 3 cords?
 
Flue Bug said:
"My stove is new so no odors yet, I was just wondering how often to have it looked at. Is six face cords= 3 cords?"

Yep... but wouldn't it be more satisfying to "look at" it yourself? You have a new stove now and you know what it looks like when it's clean. So you will be better able to distinquish the difference, no?

Good point! So, I looked in the stove behind the baffle which was kind of hard but the color is just kind of blackish brown but I can see all the pipe seams. Looks like a few places where some kind of paint has burned off a little. But, good to know what it looks like now after burning for a few weeks. So, thanks for the advice. This is just the pipe that runs from the stove to the chimney, I can't see into the chimney pipe at all. What pipe gets the most creosote first? The chimney pipe or the pipe running from the stove to the chimney pipe?
 
Unfortunately, it's the chimney that gets the creosote, generally more as you go up higher. The stove pipe tends to stay pretty hot, so you shouldn't see much, if any, building up there. Can you remove the stove pipe to get a better look up the chimney?

It's nothing to get paranoid about, since most modern stoves that are installed and operated properly don't generate much creosote. I have a boiler, which is a whole different can of worms. If you have a clean-burning setup, then once a year for cleaning is probably plenty. But you should really try to find out how it's behaving so that you know what to expect and how to proceed.
 
I can remove the stove connector pipe, or the chimney guys can, by pulling the stove out. But, where the T connector meets the chimney is behind a wall made of wonderboard so is hidden. Plus, the chimney is a flex pipe so it bends from the connection to the long pipe. Even if I could get my head back there I would see a curve. The chimney sweep is going to pull the stove out to clean the connector each time. And, if it is only a few times a year I'm fine with that.
 
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