Clogged Chimney Cap

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mtcox

Member
Hearth Supporter
Apr 6, 2007
63
Stafford, Virginia
I have a Quadrafire Isle Royale with a 12 foot chimney. After less than 10 weeks of burning, the chimney cap completely clogged. It was 100% clean prior to the burning season (I cleaned it myself). I've never had an issue through 7 seasons of burning. I have been burning a lot more poplar than I have in the past. Could this be the issue? Once that cap was off, wow! The stove took off and started heating properly again!
 

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I don't think any species of wood should do that if it seasoned. I'm guessing the screen would be the first thing to start clogging up though. I know having a screen on the cap is required by code in some areas. How was the rest of the chimney?
 
Poplar is like willow, it holds a lot of moisture. It needs thorough drying. Sounds like the issue is not the wood species but lack of full seasoning.

Good for you on solving the issue and thanks for posting the pictures. That's a classic clogged cap. If you need to burn this wood, expect to clean much more frequently than usual.
 
That cap looks pretty bad, I hope you also cleaned the chimney as it seems like it would also have a lot of buildup.

One thing, that cap looks like a Simson brand, the same as what I have, only the screen looks a lot smaller than the one that came with mine, (1/2" vs /1/4"). You could try changing the screen to a larger mesh size.

BTW I have never seen any buildup/clogging on my cap, your wood is probably not dry enough.
 
Looks to be cold flue temps... I never worry about my wood consumption,,, always burning hot enough as to never smolder the fire... Not worth the aggravation of a loaded up chimney. Because we all know what can happen next.....
 
The wood is definitely dry. It's been seasoning for three or more years. The cold flue temps could be another answer but I haven't changed the set up since I began burning seven years ago. I'll report back on the condition of the pipe itself. We have one our coldest mornings here in Virginia and I need to run it for a few more hours before I can take a peek. Thank you for the quick returns.
 
Really is not too many different things it can be. #1 thing to check has got to be the wood. Can you check a fresh split for moisture, any sizzling? Have you tried recently to go for longer burns than usual and maybe smoldered a bit too much?

Also I could see over time perhaps that as that cap ages some corrosion on the screen mesh could tend to narrow the already pretty small screen size and be more easily prone to clogging which reduces draft which causes clogging which reduces draft which.... If the wood is optimal and you're burning hot then no problem but if not you get what you got.
 
I think it is something in the air here this year mt. I am fifteen miles from ya and though my cap isn't clogged I am going to have to do a mid-season chimney cleaning here in a few hours when it warms up and the stove cools down. More accumulation in that pipe than it gets most of the time in a full season. I seriously doubt the three and four year top covered wood that has been in the shed a year is the cause.

And yeah 19 degrees at sunup this morning was cold. That load I put on at nine last night was only keeping the down stairs at 75 and upstairs at 72 when I got up at nine a.m.. >> Now if it will just cool down by one or two this afternoon I can brush the pipe.
 
BrotherBart,

I had the same thought about the stove pipe. I've only had to clean it once at the end of the season and it appears I'll be brushing it out this afternoon along with you. I have another stove in the kitchen which will keep the house tolerable today but I hate to let that Quad cool down. I need to have it roaring again by 4 PM or we'll dip into the mid sixties by 4 AM tomorrow.

I don't have a moisture meter but I can tell by the way the wood burns and keeps the house warm that I'm not having moisture issues. Maybe Santa will bring me a meter this year...........
 
Just went to get the rope and brush. Glad I did. I left it on my outdoor workbench for rain to clean the soot off of it. Dang rope is frozen solid. <>
 
I have noticed that when I have windy periods my chimney tends to cool faster and I get more creosote accumulation at the top end and especially around the cap. In fact I remember a few years ago we had a few weeks of extremely windy weather and when I checked my chimney I noticed there was even liquid creosote forming and had been dripping off the cap. Soon as the weather changed and the wind stopped blowing it went back to normal, same wood.
 
That is a lot of buildup the air must not like wood stove or something who know.
 
Your problem is the screen in the cap. Remove it and your problem will disappear. It's not just that the mesh is fine, though it really is quite fine, but a mesh is meant to filter and it is filtering your smoke. I removed mine long ago after repeated plugging with brown crunchy stuff even though the rest of the flue was very clean.

Often a topic of discussion, some people never get any accumulation on their screens and some get it so badly that we remove the screen. Look around at your neighbor's brick chimneys, you don't need a screen and without a screen your draft will improve.

I burn willow, alder, cottonwood, and other swamp woods. Maybe this makes it worse? Don't know but I have no intention of being a frequent roof dweller.
 
Wierd, I have the same DuraTech cap and screen. It's never clogged so far, but who knows, maybe this year it will. I'm going up on the roof today to clear off some windblown fir branches. I'll check out the cap while up there.
 
Good thing it's Sunday. I have a confession.

After cleaning the chimney and cap last spring, birds began to use the cap as a nest. They were able to manipulate their way into and through the stainless steel strapping. The cap had not originally come with any type of screen. The third picture in this post shows what it originally looked like. While removing the screen this afternoon, it dawned on me that I had added the screen after the birds became a problem. It never occurred to me that I should consider the size of the screen. The first picture is of the screen I added last spring and subsequently removed today. The second picture is of our second chimney cap and the screen that came with it. It's obviously a larger screen and I have not had issues. Lesson learned. Size does matter...........

Thank you for the input. I'm happy it wasn't a bigger problem.
 

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Good on you! Thought that screen was on the small side. Here's hoping everything returns to normal for you.
 
Keep an eye on it, you should get more time between cloggings with the larger filter. Ever since the days of clogging screens I have monitored the cap from the ground.
 
I have a Quadrafire Isle Royale with a 12 foot chimney. After less than 10 weeks of burning, the chimney cap completely clogged. It was 100% clean prior to the burning season (I cleaned it myself). I've never had an issue through 7 seasons of burning. I have been burning a lot more poplar than I have in the past. Could this be the issue? Once that cap was off, wow! The stove took off and started heating properly again!
You neglected to mention in your first post that you didn't have the screen for the first 7 seasons. ;)
 
If you want the stock large opening screen for it let me know. The one that came with my cap just like that is in the basement. Took it out before installing the cap. I have since replaced both caps with ones with 3/4" diamond shaped openings and have no problems.
 
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