Clogged cap

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mcollect

Member
Jan 23, 2008
130
Garrett County, Md
I cleaned my insert,Jotul 550, But it seems that the cap is clogged. There is too much snow on the roof to go up there. The insert hardly fires up and it lets smoke in the house when I go to feed it. What happens if I use my cleaning rods to knock it off? If I open the door a crack it burns fine, so could it be something else?
Thanks for any help.
 
If you don't live too close to neighbors, I've used a pellet gun. If you cant get up there to do it properly, or hire someone to do the same, tapping it with a rod should help. I guess no one here will really sanction anything but a proper cleaning.
 
I cleaned the stove pipe this morning only got about a small coffee can of crystalline flake creosote. Tried to do the cap but it doesn't seem to have helped
 
Is the cloggage happening on a screen? The junk will be all around the screen wires and pretty hard to shake off without a brush or something. It won't hurt a thing to try and jostle some of it loose with your cleaning rods. The caps are very expensive so shooting it would be low on the list for me. I would sooner try and spear the screen with the rods. Poke it. Doesn't matter if you damage the screen since it can be removed anyway.
 
Just to make clear my post...I don't suggest doing the pellet gun thing. But with the rifle/ammo used plus distance the pellets would barely dent a tin can. Don't want you to think I was destroying a stainless cap for fun. Someone mentioned once on the forums like 4 years ago, a had a buddy with a camp that had a wood stove. I may have had a beer, etc.
 
If you can't get up there . . . sounds like hiring a chimney sweep might be in order.
 
If you don't live too close to neighbors, I've used a pellet gun. If you cant get up there to do it properly, or hire someone to do the same, tapping it with a rod should help. I guess no one here will really sanction anything but a proper cleaning.
Mental note; "need new pellet gun".
 
Like Highbeam said, it's hard to dislodge that stuff on the cap screen. Did you look with binoculars to get a better idea just how clogged it may be?
 
The main purpose behind the screen in the chimney cap is to prevent hot ashes or bits of hot creosote escaping from you flue and starting a fire. Granted, the chances of that happening are probably slim except in certain circumstances. For instance, if you have dried leaves in your gutters or roof valleys it probably wouldn't take much of a spark to kindle a fire there. The other reason for a screen in a cap is to keep birds, bats, and other critters from coming down the flue and into the stove/insert. That's probably not much of a concern if you are burning 24/7 during the winter.
 
I also meant to mention that it can be dangerous burning a stove/insert with a clogged cap. If the gasses in the stove can't exit out the flue due to a clogged cap they can instead enter your home through your primary and secondary air inlets once the fire dies down and you lose your draft. As you know carbon monoxide is odorless and deadly.
 
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Mine clogged last year, I could see from the bottom, looking inside the flue itself was clear. I used an airsoft machine gun to dislodge a lot of it. At the start of this season, I just pulled it off once we were past critter season. :)
 
The main purpose behind the screen in the chimney cap is to prevent hot ashes or bits of hot creosote escaping from you flue and starting a fire.

In the old days with fireplaces, open flues, and people burning trash this might have been true. A chunk of burning carboard can certainly float pretty well.

In a modern stove burning firewood I see no value in the screen except to keep birds out. I don't have that problem and am screen free for many years now.
 
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Woody yes I looked it is pretty clogged. What happens if I just remove it?
There's a possibility that the clogged screen is indicative of creosote build up in the pipe too. If this is hard to reach can you brush bottom up with either rods or a sooteater?

Do you know what the buildup?
 
Be Green I cleaned the pipe thoroughly and looked at it with a flashlight. bright clean metal as far as I could see. My cap has rectangular mesh that is impossible to clean from inside. Every two or three years I go up and take it off to clean. This in the shoulder season it drafted fine, now that the roof is snow covered it seems to be clogged. Wood is between 12 and 14%.
 
I use a sooteater from the stove up. The first time, I pushed the cleaning end all the way up into the cap. It helps to have someone outside visually watching. Then I turned on the drill and it cleaned the cap quite well. It really knocks around in there. If you're not familiar with a soot eater, it has a ball with stiff bristles that bounce around with the action from a drill. Perhaps it might be enough action to dislodge the build up. How much wider is the screen than the liner?
 
I had the same problem with mine. My chimney is 6" stainless steel, 25' high straight vertical from the stove to the top of the chimney. I noticed crud accumulating round the vents and the ridge on the cap. Also, I was getting a lot of smoke smell in the house when reloading. Looked at the cap with binoculars, and sure enough the vents in the cap appeared to be almost entirely plugged.

I always do a cleaning of the chimney mid season anyway, using a Sooteater, and it was just about time. When I opened the cut-out at the bottom of the flue, I collected a pretty good size pile of creosote. The flue looked pretty clean, just black with little noticeable accumulation. I cleaned it with the Sooteater. When I extended the rods all the way to the top, I made sure I gave it a good spin when I could feel the rod gently touching the top of the cap. My wife stood outside and said she could see a lot of black stuff flying out the vents. Afterwards, looking up the chimney I could see a lot more daylight, and looking through the binoculars the vents look a lot cleaner now. When done, I had less than a full coffee can full of creosote. The cool temperature outside must cause the smoke to condense right at the cap where it comes out the vent holes.

The flue draws a lot better now. I smell a lot less smoke after reloading.

I don't have a screen on mine, just for that reason. I figured it would clog up with soot. The house has a metal roof, so I don't worry too much about sparks flying out the chimney. I do sometimes get birds in the stove in springtime, but I just keep the damper open and check every day or two, and capture any birds in the stove and take them outside to release them. This spring we didn't have any birds in the stove, and I wondered why. I suspect the cap vents were already clogged and I didn't get them cleared when I cleaned the chimney at the end of last season, so the birds didn't have any opening large enough to enter. From now on, I'll pay more attention to that.
 
Mine don't have screens. Last summer I heard something weird coming out of the wood furnace in the garage so I opened the door and a <expletive deleted - BB> black bird flew out. They build nests in their 20-30' down in the summer.
 
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The only bird I have ever had in mine is chimney swifts. They fly down into the chimney, but the interior wall of the stainless steel tube is too slick for them to hold onto, so they slide all the way down to the bottom. Their only exit is through the stove. I keep the damper open so they don't leave a mess inside the AB and damage the very fragile combustion package, plus this allows them to exit the stove pipe into the fire box, as they see daylight coming through the glass door.

I try to capture and release them before they die inside the stove. I don't wish to harm them, since they are beneficial birds that eat a lot of insects, and I believe they are a protected species making it illegal to kill them.

It's interesting why they build nests and reside in chimneys. Originally, they lived in hollow trees, but as more and more forest land was developed, they found chimneys to be a readily available substitute as their native tree habitat diminished.

I've heard them mistakenly called "chimney sweeps". That's an appropriate name, because as they flutter around in the chimney trying in vain to grab hold of the smooth metal surface, they can do a pretty good job of cleaning the chimney. I have done my spring chimney clean after having birds in the stove, and nearly all the creosote and soot was already in a pile at the bottom of the tee.
 
Mine clogged last year, I could see from the bottom, looking inside the flue itself was clear. I used an airsoft machine gun to dislodge a lot of it. At the start of this season, I just pulled it off once we were past critter season. :)

That story may have been what gave me the great idea! Sounds familiar
 
The screen on my liner cap was skipped by the hired sweep, so resulted in a trip from the local fire department shortly after starting to burn for that season to ventilate the house of CO. I decided to remove that potential failure mode by removing the liner screen and installing a big stainless cover with a large grate over my whole chimney with its two flues. Ever since I have had horrible problems with too much draft. Stove eats wood at a much faster rate and sounds like a freight train when the door is cracked. No more plugging issues, but that cap, even when clean, provided some beneficial flow restriction in my install.
 
Michael wrote: yes I looked it is pretty clogged. What happens if I just remove it?

Problem is, those are primarily rain caps. Leave it off, and you have water flowing down the chimney every time it rains, sleets or snows. That can create a big mess, not to mention rust, corrosion and just plain water damage. I'd doubt they should clog up during one burning season even if the stove burns dirty from time to time. I think I failed to properly clean mine at the end of last year's burning season.
 
I'd doubt they should clog up during one burning season even if the stove burns dirty from time to time. I think I failed to properly clean mine at the end of last year's burning season.

Oh no, the cap screens can easily be clogged every couple of months even when burning good fuel properly. The time to cloggage has to do with size of the mesh, size of the cap, and yes you can gunk it up with poor burning habits. Many of us had screen cloggage while the rest of the flue was very clean.
 
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mcollect,

if you are using paper or cardboard inside your stove, it could be a source of debris that is sticking on the screen. invest in super cedars and avoid any paper in the stove.

Have you tried burning hot with the air wide open or with door slightly ajar to try to clean the cap with heat from the stove exhaust?
 
I don't get much build-up, but the sooteater knocks away what there is on a bottom up cleaning.
 
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