Can't Get My Secondary's To Kick In

[ckdeuce]

I'm running a Century (FW300010) 2000sq' stove connected to 5' flue pipe then into double wall Supervent straight throught the housed, no bends. The total chinmey length including the black pipe is about 21". The wood I am using is fairly seasoned, but a day after delivery we had I nice ice and snow storm. I wasn't able (ok just plain lazy) to stack it for over a week. The wood burns fine, a sizzle for the first 5-10 min and then I get good charring. Typcally I run the stove almost 100% until I get a hot bed of coals. I rake forward and reload with about 5-7 5" splits and run full air unitl I get good charring and a flue them of 500-600 degrees on a magnetic guage. At that point I shut the air down to 50% and back off more and more. The fire is burning well, but I don't get any secondary burn. I had some going last night, but it was short lived. Also, those 5-7 small splits only last about an hour or so. Seems like I go through a lot of wood.

Any suggestions? Thanks

 

[swestall]

Surprising, what happens when you close the damper down to say 1/4 when the wood is charred?

 

[swestall]

https://www.hearth.com/econtent/index.php/forums/viewthread/15553/

Also, take a look at this info...

 

[ckdeuce]

Surprising, what happens when you close the damper down to say 1/4 when the wood is charred?

Wood burns fine, but no secondary burn. Flames dance up to the tubes, but no push or air from the holes. Almost like they are clogged, but the stove is less than a month old. There are times when I see the secondary's kick in, but it is hit and miss, and never lasts.

 

[swestall]

Is your stovetop temp up to 500+? It sounds like the wood may be holding down the combustion; perhaps not seasoned. If you can get some known dry wood, a bundle at HD or Lowe's for instance, and see what happens with that, it would tell you a lot.

 

[Corey]

Well, first off, you say the total chimney length is ' 21" ' as in 21 inches? I guess (hope) you mean feet or - 21'. That sound OK. Second, you say 'the day after delivery...' So I take it you bought wood from 'the firewood guy' which will almost guarantee it's not dry - especially this late in the season. Plus you mention the sizzle, running the stove 100%, and going through a lot of wood, which are all signs that the wood isn't really dry.

I don't know about others, but I see the biggest secondary flames right after I put in new wood - that is when most of the volatiles are baking off and my secondary pipe looks like a big gas burner shooting out big flames. When the wood is all 'on fire', my secondaries die off because all the 'smoke' is being burned at the surface of the wood.

Overall, it sounds like a case of wet wood. Even thought it is not actively 'sizzling' it can be putting out water vapor which keeps the flue gases cool, lowers your heat output and can quench secondary flames. If you have access to any kiln dried lumber scraps, you could get the stove up to temp, then chuck a few of those in there and see what kind of secondary burn you get.

 

[ckdeuce]

Maybe it is my 21" chimney..... My bad, yeah it's 21' Stove top temp is @ 500-600. I'll try picking up some bundled wood at lowes and give that a shot. Thanks for all the advice.

 

[Corie]

Temp. sounds good, stack sounds good. I"m pointing the finger at the wood.

 

[eernest4]

How hard would it be for you to find the secondary air intake an blow some compressed air through there to make sure that the secondary air pipes are not clogged somewhere??

Also, i am highly inclined to look to see if there is a secondary air control valve that is nearly shut off or that is not linked properly or disconnected altogether, from the single lever dual action primary & secondary air control lever/ knob.

Sorry, I am not fimiliar with a century stove. Pull out your owner's manual & look see where the secondary air intake is & if it has a air adjustment orfice or valve of some type & make sure that valve opens & closes as it is susposed to.

I burn some high moisture wood ,mixed in with some dry & well seasoned wood, as they got all mixed up in my wood shed one day when the wood pile fell over.

I been doing it 16/7 & 24 /7 all year & never hit a problem engaging secondary burn & my stove is a DIY conversion of a 1970- 1/4 plate steel, 12 cubic foot firebox front loading ex smoking dragon that does not even have a baffle plate in it , but has some kick ash secondary burn tubes that used to be a domestic hot water coil before I converted it by drilling a friking lot of holes through the domestic hot water pipe.

My guess is that the secondary pipes are either clogged by foriegn matterial or the secondary
air contol is stuck in nearly the off position.
blowing through the pipe would let you know if the pipe is clogged & inspection will tell you if the secondary air control is shut down.

SOMEBODY HAS TO STATE THE CONTRARY THEORY & BE THE DEVIL'S ADVICATE.

When I first converted my stove , I had the same problem as you, secondary burn maybe ,if the stove felt like it & maybe not. I had drilled secondary air holes 1 every 6 inch of pipe & 5/32th in dia drill bit.

My fix was to drill holes every 3 inch of pipe & go to 3/16th drill bit.
double the number of holes & the next larger size hole & now I can force secondary burn despite anything the stove wants to do , but its still easier to initiate S.B. at 550 deg than at a lower temp.

Best of luck & keep my advise in mind in case dry wood don't work out so good.

 

[moshiersr]

On a century fw300010 there isn't any secondary air control.. just the primary. Secondary is just two holes in the back bottom of the stove.

I just did an upgrade of my baffle to try and get secondary burn to light in quicker and stay in longer.. So far so good... I think the steel baffle takes and absorbs a lot of heat from the stove when burning wood that isn't exactly perfect..

I used Duraboard ceramic fiberboard and Kaowool to build my upgraded baffle. It lights off 10 times quicker and seems to make the stove burn longer..

 

[begreen]

Sounds like the wood to me. Try splitting a batch of the 5" splits in half and let them sit in the warm house for several days. If possible stack them so that a lot of air can circulate around the stack.

Then build a fire using them. If you have secondary ignition, then it's the wood.