Spark arrestor plugged?

[racer765]

I have an older Century FW24007 wood burner with a new 6" stainless chimney that is straight (no bends) 24 ft long. I have only used it a handful of times since the new chimney pipe install a few months ago until last week when I have been using every day with the colder temperatures. I noticed it was getting harder and harder to get a good draft and it was getting hard to reach the 800-1000F flue temp during the first burn of the day. Yesterday I noticed a lot of back draft and with the wood burner door open it would smoke profusely from the pipe joints. I figured there was a restriction at the cap since it was such a low time of use. I climbed up the roof today in 16 inches of snow to find the spark arrestor was almost plugged solid with a dark dry ashy substance. What could have caused that with only a total of a month's worth of use on a new chimney? The wood I burn is very dry, aged 5 plus years in a covered woodshed. It tests at an average 5-7% moisture content with some pieces reading 2% or less. Its mostly a mixture of oak and ash with a few pieces of dry pine mixed in. I reduce the draft at night to try to slow the burn and prolong the fire but I try my best to keep it with a flame and not smoldering.

I had added the spark arrestor to the cap to keep birds out etc. should I just leave it off?

Thank you.

 

[EatenByLimestone]

Good stove! I happily ran one for years!


It’s a real easy breather, I was able to run mine off a horribly marginal chimney. It’s possible you have enough draft with this cold weather to suck ash and such up where it gets caught on the screen. What was the chimney before you changed it? Why are you trying to get the flue so hot?

 

[begreen]

It's possible that the screen is too fine. How did the chimney pipe look while you were up there?

 

[racer765]

Good stove! I happily ran one for years!


It’s a real easy breather, I was able to run mine off a horribly marginal chimney. It’s possible you have enough draft with this cold weather to suck ash and such up where it gets caught on the screen. What was the chimney before you changed it? Why are you trying to get the flue so hot?

Hello, the chimney before was a square block chimney with a clay liner. Before I used it I had the chimney inspected and the clay liner was cracked and falling apart. We attempted to remove the clay liner to do a stainless liner in the chimney but the outer block started to crack apart. I found it cheaper and easier to remove the block chimney and install the stainless chimney pipe in it's chase. We run the flue temp high for the first part of the day from what I had read online to keep the chimney clean. The rest of the day flue temp averages 400-500F degrees. Occasionally it drops to 250-300F if I get side tracked and wait too long to reload.

 

[racer765]

It's possible that the screen is too fine. How did the chimney pipe look while you were up there?

The chimney pipe looked good. I had previously borescoped the chimney and the walls were clean with no buildup visible on camera. The cap after I pulled out the screen had a dry dark powdery soot on it.

 

[begreen]

What is the mesh size in the screen? If it's less than 1/2", replace it with something coarser.

 

[Trevor Tahclep]

Had that problem way back when with 1/4'' mesh, changed it to 1/2'' or maybe it is 3/4'' and have never had that problem again.