Plugged chimney cap

First: 30-NC stove, 18ft total of duraplus dvl doublewall pipe, chimney and cap, softwoods (pine, aspen, douglas fir, a little tamarack) seasoned for 2+ years.

I installed this stove this fall. It burns well, and I have been very pleased with its performance. About 2 months of shoulder season use to date.

This week we started getting smoke into the house when opening the door for reload. It progressively got worse, so today I finally got the chance to check the chimney (beautiful day, sunshine, 50 degrees!). It has been very rainy the last few weeks, and I didn't feel like going on the roof.

What I found was that the chimney was quite clean, but the cap was mostly plugged. It was flakey and brushed off pretty easily. I am sure the stove will burn better now, will try later when the sun drops.

I was up there about a month ago and had the cap off, and didn't note a problem at that time. Some heavier burning since then, and lots of rain. I do try to burn clean (without visible smoke), but towards the end of a burn it does smoke.

I didn't have this happen with the allnighter, but then again I didn't have a screen on the cap at that time.

So, any advice for keeping the cap cleaner? Is this a normal problem?

 

Seems kind of odd that you say it smokes toward the end of the burn. Usually very little smoke during the coal stage of the burn. I do open the air on the 30 as the burn progresses, but that is to maintain a higher stt for more heat not because of smoke.

 

It is what came on the duravent cap, about 1/2" holes.

 

I may be wrong on that, I should get out and look again next time. But I am pretty sure that when we let it die down (leaving the house for a few hours), I usually see some smoke from the chimney.

 

Great point, and starts from a dead cold stove you don't get a nice coal bed before loading full...I've had the bottom two outside splits still solid after an overnight burn, I imagine they smoldered a bit as the burn got to the end with the air turned down.

 

I don't use a screen and have about the same height flue system...all 2X wall.
I'll get a slight bit of buildup, but it doesn't clog up like that. I'd lose the screen to see how it does.
I do get some smoke toward the end of a burn, even with full air.

 

Sorry, it is dark now, and can't get a photo. But it is this cap.

DuraVent DuraPlus 6 in. Round Chimney Cap-6DP-VC - The Home Depot

Is the screen primarily a spark arrestor or to prevent animal entry?

 

That's just animal/bird screening.

 

The description implies it is a spark arrestor?

 

Yep, I got that, and it is a metal roof to boot.

 

A lot of people take their caps (or at least the screen) off when burning...I had one on an old smoke dragon that would plug up every two weeks...it went away for the winter...end of problem.

 

I have two duravent chimneys. I bought the second one without the optional screen in the cap. I did this because the screen in my first duravent cap would clog like crazy with light brown crunchy junk above a clean flue. I took the cap apart and removed that screen.

I do not miss climbing up onto the roof several times each winter. Yes, I've had a few birds fall in during the summer.

 

Make sure the screen is not required by law. On the wet side of the cascades it's not as big a deal as where it is drier and higher potential for wildfires on the eastern slope. Cutting a safety device out could open one up to liability associated with starting a forest fire. Just make sure you make an informed decision. This is an excerpt from the inspection checklist from the WA Dept of Labor and Industries.

"Chimney system extends 3 feet above roof and 2 feet above the highest part of the roof within 10 feet of the chimney and terminated with an approved spark arrestor, and a storm collar is installed. "

Here's the site.

http://www.lni.wa.gov/Forms/pdf/622015a0.pdf

 

Thanks, I was looking for this. I live in the woods, on the dry side of the Cascades, I think I will be leaving it alone. I'd hate to be the one who starts the next wildfire.